Position Overview

The successful candidate performing will work in the mechanical analysis, thermal analysis and life prediction life soldered to a PCB and activities including design, and testing for electronic units and PCBs.

The successful candidate will be innovative, creative, and challenge the status quo. He or she will work well in teams while also having the ability to work assignments autonomously.

Key Responsibilities

• Execute the design, analysis, or evaluation of assigned projects using sound engineering principles and adhering to business standards, practices, procedures, and program requirements.
• Mechanical design and modelling of electronic component for space applications. Preparation of preliminary design with layouts, sketches, preliminary strain analysis to support trade studies, using of fatigue models for the component terminations (SMD, thru hole, BGA), testing requirements, materials and processes.
• The use of fast ageing models to test quicker and assess the component life prediction in the solder.
• Develop and maintain design documentation: mechanical reports, thermal reports, joint fatigue reports, test procedures.
• Troubleshoot and investigate component anomalies and failures, perform root-cause analysis, and provide resolution.
• Develop mechanical/structure test plans and procedures, identify hardware needs, design of test set-ups.

Qualifications

Education

Bachelor's degree in Mechanical Engineering or related technical field. Higher degree is preferred.

Experience

Minimum 5 years of hands-on experience in joint fatigue analysis and testing of components.

Required Qualifications

• Strong technical skill in stress, strain, fatigue, including FEM computer methods using standard analytical tools and classical structural analysis methods. (ANSYS). Specific for components soldered to substrates or PCBs.
• Knowledge/experience of thermal cycling and fast aging models (Englemaier, Norris-Landzberg).
• Ability to perform analysis using APDL (code), to automatize analysis, and export only required results.
• Demonstrated ability to work in a multidisciplinary team with other engineers.

Soft Skills

• Flexibility/adaptability in a fast-paced & dynamic environment
• Excellent English written and verbal communication skills.

Technology Stack

• ANSYS, and APDL.
• Excel and Word macros in vba.
• CAD software: Autodesk Inventor, Vault
• Shop-floor tools, purpose is analysis correlation.

Physical Requirements

• Ability to support national and international business travel occasionally (expected <5% of the time)

This job description may not be inclusive to the duties and responsibilities listed. Additional tasks may be assigned to the employee from time to time or the scope of the job may change as needed by business demands. 

Who we are

The role

The day-to-day

• Defining system and component-level specifications

• Designing schematics for complex electronic systems

• Developing MCU firmware for real-time embedded applications

• Performing PCB layout design, from initial concept through to manufacturing

• Defining and executing validation and test plans

• Contributing to system-level design and architecture decisions

• Troubleshooting and debugging electronics and electrical systems across hardware and firmware

You should apply if you

• Have 5+ years of experience designing electronics, including schematics, PCB design, and firmware development

• Hold a BSc in Electronics Engineering or a related field (MSc preferred)

• Are proficient in both English and Spanish

• Are able to work independently, owning projects end-to-end from concept through to validation

• Thrive in a fast-paced, innovative environment where no two days are the same

Note: We operate in an industry where women, as well as other minority groups, are systematically under-represented. We encourage you to apply even if you don’t meet all the listed qualifications; ability and impact cannot be summarised in a few bullet points.

Nice to Have

• Experience with C2000 MCUs or similar DSP-oriented microcontrollers purpose-built for motor control

• Proficiency with advanced debugging tools, such as hardware debuggers, oscilloscopes, and motor control-specific profiling tools

• Experience with CAN, SPI, UART, or other embedded communication protocols in real-time systems

• Background in high-performance student engineering projects, such as Formula Student or similar competitions

• Familiarity with robotics or robotic actuation systems

• Experience working in a startup or R&D environment, where adaptability and initiative are key

Join Helsing and work with world-leading experts in their fields 

• Helsing’s work is important. You’ll be directly contributing to the protection of democratic countries while balancing both ethical and geopolitical concerns

• The work is unique. We operate in a domain that has highly unusual technical requirements and constraints, and where robustness, safety, and ethical considerations are vital. You will face unique Engineering and AI challenges that make a meaningful impact in the world

• Our work frequently takes us right up to the state of the art in technical innovation, be it reinforcement learning, distributed systems, generative AI, or deployment infrastructure. The defence industry is entering the most exciting phase of the technological development curve. Advances in our field of world are not incremental: Helsing is part of, and often leading, historic leaps forward

• In our domain, success is a matter of order-of-magnitude improvements and novel capabilities. This means we take bets, aim high, and focus on big opportunities. Despite being a relatively young company, Helsing has already been selected for multiple significant government contracts

• We actively encourage healthy, proactive, and diverse debate internally about what we do and how we choose to do it. Teams and individual engineers are trusted (and encouraged) to practise responsible autonomy and critical thinking, and to focus on outcomes, not conformity. At Helsing you will have a say in how we (and you!) work, the opportunity to engage on what does and doesn’t work, and to take ownership of aspects of our culture that you care deeply about

What we offer

• Competitive salary and VSOP options

• Learning: €500/£450 yearly allowance

• Health & wellness: gym membership and mental health support (Nilo.health)

• Social: regular company events and monthly social allowances

• Enhanced parental leave: 22 weeks fully paid for primary caregivers & 6 weeks for secondary caregivers

• Family support: 5 days of paid family emergency leave, 100% remote work option during pregnancy and phased return to work

• A hands-on onboarding program (affectionately labelled “Infraduction”), in which you will be building tooling and applications to be used across the company. This is your opportunity to learn our tech stack, explore the company, and learn how we get things done - all whilst working with other engineering teams from day one 

Helsing is an equal opportunities employer. We are committed to equal employment opportunity regardless of race, religion, sexual orientation, age, marital status, disability or gender identity. Please do not submit personal data revealing racial or ethnic origin, political opinions, religious or philosophical beliefs, trade union membership, data concerning your health, or data concerning your sexual orientation.

Who we are

The role

At Helsing we deliver AI-based capabilities and the enabling foundation that allow machines to perceive and assist human decision-making. You will have the unique opportunity to shape AI capabilities in one of the most challenging sectors, where high generalisation capabilities need to be paired with hardware constraints and real-world robustness.

You will be part of a team pushing the boundaries of autonomous robotics through reinforcement learning. Your work will focus on designing, training and deploying RL-based controllers for robots operating in complex, unstructured, and dynamic real-world environments — where classical control approaches fall short. This includes enabling robots to perceive and understand their surroundings by fusing rich sensory inputs, including vision, to inform robust and adaptive control. You will own the full pipeline from simulation to deployment, ensuring that learned policies are robust, efficient, and ready for real-world operation under tight hardware constraints.

You should apply if you

• Hold an MSc or PhD in Robotics, Machine Learning, Control Engineering, or a closely related field, with a strong focus on reinforcement learning and robot control.

• Have hands-on experience training and deploying RL-based controllers on real robotic hardware, not just in simulation — you have seen your policies fall, iterate, and ultimately succeed on a physical system.

• Are deeply familiar with modern RL techniques for continuous control, including but not limited to: model-free methods (PPO, SAC, TD3), model-based RL, hierarchical RL, sim-to-real transfer strategies, domain randomisation, and curriculum learning.

• Have a solid understanding of robot dynamics, kinematics, and classical control theory (e.g. PID, model predictive control, trajectory optimisation), and know when and how to combine them with learned approaches.

• Are proficient in building and working with physics-based simulators (e.g. MuJoCo, Isaac Gym/Isaac Lab, PyBullet, Gazebo) for training and validating RL policies.

• Possess solid software engineering skills, writing clean and well-structured code in Python and/or languages like Rust or modern C++, and have experience deploying AI software to production including testing, QA, and monitoring.

• Have excellent communication skills and the ability to report and present research findings clearly and efficiently, both internally and externally.

• Are passionate about keeping up to date with current research and enjoy re-implementing and extending state-of-the-art papers.

Note: We operate at an intersection where women, as well as other minority groups, are systematically under-represented. We encourage you to apply even if you don’t meet all the listed qualifications; ability and impact cannot be summarised in a few bullet points.

Nice to have

• PhD in Robotics, Reinforcement Learning, Control Engineering, or related fields, with publications in top-tier venues (e.g. CoRL, ICRA, NeurIPS, ICLR, IROS, RSS).

• Experience developing controllers for highly dynamic robotic systems operating under complex contact interactions and demanding environmental conditions.

• Experience with vision-based perception for robotics control, such as depth estimation, visual odometry, or visuomotor policy learning.

• Familiarity with low-level motor control interfaces and real-time embedded systems constraints.

• Experience with online adaptation and meta-learning techniques to enable robots to adapt to changing environmental conditions

• Experience with sensor fusion (IMU, proprioception, exteroception, vision) to inform and enhance learned control policies.

Join Helsing and work with world-leading experts in their fields

• Helsing’s work is important. You’ll be directly contributing to the protection of democratic countries while balancing both ethical and geopolitical concerns. 

• The work is unique. We operate in a domain that has highly unusual technical requirements and constraints, and where robustness, safety, and ethical considerations are vital. You will face unique Engineering and AI challenges that make a meaningful impact in the world. 

• Our work frequently takes us right up to the state of the art in technical innovation, be it reinforcement learning, distributed systems, generative AI, or deployment infrastructure. The defence industry is entering the most exciting phase of the technological development curve. Advances in our field of world are not incremental: Helsing is part of, and often leading, historic leaps forward. 

• In our domain, success is a matter of order-of-magnitude improvements and novel capabilities. This means we take bets, aim high, and focus on big opportunities. Despite being a relatively young company, Helsing has already been selected for multiple significant government contracts.  

• We actively encourage healthy, proactive, and diverse debate internally about what we do and how we choose to do it. Teams and individual engineers are trusted (and encouraged) to practise responsible autonomy and critical thinking, and to focus on outcomes, not conformity. At Helsing you will have a say in how we (and you!) work, the opportunity to engage on what does and doesn’t work, and to take ownership of aspects of our culture that you care deeply about. 

What we offer

• Competitive salary and VSOP options

• Relocation support: up to €2,500 and 4 weeks temporary accommodation

• Learning: €500/£450 yearly allowance

• Health & wellness: gym membership and mental health support (Nilo.health)

• Social: regular company events and monthly social allowances

• Enhanced parental leave: 22 weeks fully paid for primary caregivers & 6 weeks for secondary caregivers

• Family support: 5 days of paid family emergency leave, 100% remote work option during pregnancy and phased return to work

These are the core benefits across all locations, there may be additional benefits in certain locations.

Helsing is an equal opportunities employer. We are committed to equal employment opportunity regardless of race, religion, sexual orientation, age, marital status, disability or gender identity. Please do not submit personal data revealing racial or ethnic origin, political opinions, religious or philosophical beliefs, trade union membership, data concerning your health, or data concerning your sexual orientation.

About Proton

Join Proton and build a better internet where privacy is the default

Proton was founded in 2014 by scientists from CERN on a simple truth: privacy is a fundamental human right. Since then, we’ve built the world’s largest encrypted email service (Proton Mail) and expanded into Proton VPN, Proton Drive, Proton Pass, and Proton Calendar—tools used by millions globally to protect their freedom, fight censorship, and keep their data safe. In some situations, Proton has literally helped save lives!

We are profitable, independent (no VC control), and selectively hire from the top ~1% of applicants. Our 500+ team members across 50+ countries come from leading organizations and elite academic backgrounds. We move fast, keep hierarchy light, and prioritize impact over optics. If you want to do meaningful work with exceptionally high-caliber people, this is it. Join us and do work you can truly be proud of. Check our open-source projects here!

The team:

Join a world-class Linux engineering team at the forefront of privacy-focused open-source development, where your contributions directly impact millions of users worldwide. Our engineers are passionate problem-solvers who thrive in a fast-paced, collaborative environment, tackling complex technical challenges with creativity and rigor. We value autonomy, technical excellence, and a shared commitment to building software that genuinely makes the world a safer place. If you are driven by purpose and love working alongside exceptionally talented people, you will feel right at home here.

What you will do:

• Design, develop, and maintain robust automated test frameworks and pipelines for Linux-based open-source software

• Write and execute functional, integration, regression, and end-to-end test suites to ensure product reliability and security

• Collaborate closely with developers to define testability requirements and integrate automated tests into CI/CD workflows

• Identify, document, and track software defects, working with engineering teams to drive timely resolution

• Perform exploratory and risk-based testing with a strong focus on privacy, data integrity, and security compliance

• Develop and maintain test infrastructure, including virtual machines, containers, and Linux environment configurations

• Analyze test results, generate reports, and provide actionable insights to improve software quality and release confidence

• Contribute to the continuous improvement of QA processes, tools, and best practices across the engineering organization

• Participate in code reviews for test code, ensuring maintainability, scalability, and adherence to engineering standards

• Stay current with the latest Linux ecosystem developments, testing methodologies, and open-source tooling

What we are looking for:

• 3–5 years of hands-on experience in software test automation, with a strong focus on Linux-based environments

• Solid proficiency in at least one scripting or programming language commonly used for test automation, such as Python, Bash, or Go

• Proven experience designing and maintaining automated test frameworks (e.g., pytest, Robot Framework, or similar)

• Good understanding of CI/CD pipelines and experience integrating automated tests with tools such as GitLab CI, Jenkins, or GitHub Actions

• Familiarity with containerization and virtualization technologies, including Docker, QEMU, or similar tools for test environment management

• Solid knowledge of Linux internals, system administration, and command-line tooling

• Experience with version control systems, particularly Git, and comfort working in an open-source collaborative development model

• Understanding of software security principles and privacy-by-design concepts is a strong plus

• Ability to read and understand application source code to improve test coverage and identify edge cases

• Strong analytical and problem-solving skills, with a structured and detail-oriented approach to quality assurance

• Good communication skills and ability to work effectively in a remote, internationally distributed team

• A genuine passion for open-source software, privacy, and building technology that has a positive impact on society

What We Offer:

• Work that Matters: millions of people trust Proton with their privacy. We answer only to our users — not advertisers, not investors with conflicting agendas, not governments. The work you do here is real, and the impact is measurable. (read more about our impact here)

• Stock Options: at Proton, we all have the opportunity to be owners of the company. From day one, you have a real stake in what we're building. When Proton wins, you win.

• Technology: you'll get the right hardware and the right software you need to do your best work.

• Learning & Development: we invest in your growth because sharp people make us better. Proton is one of the fastest ways to accelerate your career because you'll be thrown into real challenges, with real ownership, from day one.

• Employee Benefits: your wellbeing isn't an afterthought. We offer strong health coverage, solid retirement options, generous leave, and wellness support so you can bring your best self to work every day

• In-Person Collaboration: Amazing things happen when passionate, smart, and purposeful people get together in the same room. With offices across Geneva, Zürich, Barcelona, London and more, you'll spend most of your time collaborating face-to-face with people who genuinely care about what they're building

• Food: Lunch and snacks are on us every day in our offices so you can focus on the work and not on what's for lunch.

• Transport: getting to the office shouldn't cost you. We cover public transport, bike allowances, or parking, whichever works for you.

• Flexible Working: you own your schedule. Set hours that work for you and your team — because outcomes matter more than when the clock says you started.

Our Commitment to Diversity and Inclusion

At Proton, we believe diversity drives innovation and strengthens our mission to provide privacy as a default for all. We are committed to fostering an inclusive environment where all individuals, regardless of race, ethnicity, gender, age, sexual orientation, physical ability, or socio-economic background, feel valued and empowered. We strive to create equal opportunities, promote open dialogue, and support continuous learning to ensure every voice is heard and respected.

If you need any extra support or reasonable adjustments during the hiring process, please let your talent partner know.

Candidate Privacy Notice

When you apply for a position, refer a candidate, or are considered for a role at Proton Technologies AG (Proton, we, us, or our), your information is stored in Greenhouse, in accordance with their Service Privacy Policy. This information is used to evaluate your suitability for the posted position. We also retain this information for consideration for future roles that you may apply for or that we believe may align with your background and skills.

If we no longer have a legitimate business need to process your information, we will either delete or anonymize it. Should you have any inquiries about how we use or manage your information, or if you wish to access, correct, or delete your data, please contact our privacy team at careers@proton.ch.

Proton does not accept unsolicited resumes from any sources other than directly from candidates. We will not pay a fee for any placement resulting from an unsolicited offer, even if the candidate is subsequently hired by Proton.

To learn more about our privacy policy, please visit our privacy policy page.

Salary range (Vilnius) - 46.100 - 60.000 EUR gross annual 

#LI-Onsite

Wallapop is a Barcelona based scale-up driven by the purpose to empower people to embrace a more conscious and human way of consumption. We believe in a world where collaborative economy is mainstream. This is what drives us. 💫

Wallapop operates in Spain, Italy and Portugal, offering a catalogue of several hundreds of millions of products and services. Powered by technical innovation and continuous improvement, we bring together the scale & trust of classifieds with the marketplace’s convenience & reach. 🌱 Our mission is to enable a connected trade ecosystem, making 2nd-hand the norm through smart use of technology.

The Challenge 🧩 

Some of the interesting things we are currently doing include finding new ways to handle complexity and improve resiliency. We leverage various AWS technologies (compute, storage, etc.) to meet our objectives. At Wallapop, as a Backend Engineer, you'll have ownership of team microservices, fully embracing the DevOps philosophy. Our tech stack includes the following:

• Kotlin & Java
• Spring Boot & Ktor
• Kafka & RabbitMQ
• MySql, DynamoDB, Redis & RedShift
• Docker
• Solr & ElasticSearch
• AWS: S3, ECS, RDS, Lambdas, CloudWatch, MSK, SES, CloudFront & more

What You Will Do 👇

• Write and maintain robust, scalable code in Java or Kotlin, depending on your team's specific stack.
• Develop new features using Domain-Driven Design (applying both tactical and strategic design principles).
• Modernize and refactor legacy components to ensure long-term system health.
• Champion software quality by implementing comprehensive testing strategies, contributing to a collaborative and reliable code review culture.

What We’re Looking For 🔎

• Demonstrated problem-solving skills and the ability to think critically about complex technical challenges.
• A quality-driven mindset with a pragmatic focus on detail and delivering value.
• Adaptability and a genuine eagerness to learn, share knowledge, and grow within a dynamic team.

Do note that all our jobs are 📍 Barcelona based. We follow a hybrid model where flexibility rules. We commit to a minimum of 6 days per month in the office. Each team self-organizes to decide on cadence and in-person/remote rituals.

Wallapop is an equal opportunity employer. We celebrate diversity and are committed to creating an inclusive environment for all employees as we want Wallapop to be a place for everyone.

Additionally to the opportunity to contribute to an agile product set up and work together towards achieving our meaningful mission, we offer the following 🍭 Perks & Benefits:

• Generous individual learning budget of 2k per year
• Free office meals, lunch selection from different providers
• Group and individual English, Catalan & Spanish lessons as part of our working day
• Private Health Insurance with Alan
• Flexible working hours + Intensive Fridays
• Flexible remuneration to deduct from gross salary (kindergarten/food/transport check)
• Gym & Wellness plan, including physiotherapist in the office
• Generous referral Program & Charity Donation
• Bonus for weddings & newborns
• Wallapop Renta (Tax income support)
• Monthly plan for free shipping, bumps & home-pick-up on our services
• Work anniversary Gifts and Birthday Surprises
• Contribution towards your WIFI in your monthly payroll
• One-off payment based on compensation package to go towards setting up your home office
• Relocation package (monetary support and legal advice) and visa sponsorship, if applicable
• 26 holidays per year
• TOP hardware of your choice (latest Apple or Windows)

What does the hiring process for this position look like? **Please, note that all interviews take place remotely over hangouts.**

• Intro Call - run by Talent Acquisition, focus on providing more information about the role and the company as well as going over your experience, motivation, and expectations. This usually takes 45-60 minutes.
• Technical Task - you will be assigned a test that consists of a coding challenge to assess the technical skills required for the role. You will have up to 7 days to complete it
• Expertise Interview - run by the core team, focusing on the hard skills and the ability to deliver in a given context. This usually takes 60-90 minutes.
• Stakeholder Interview - run by the hiring team and relevant stakeholders, focus on the ability to collaborate & deliver in a cross-functional set-up. This usually takes 60 minutes.
• Culture-Add Interview - run by culture interviewers, focus on adherence to Wallapop's purpose and business proposition. This usually takes 60 minutes.
• Offer - should you be the right candidate, your offer will be discussed over a call with talent acquisition and will then be confirmed in writing.

Wallapop is a Barcelona based scale-up driven by the purpose to empower people to embrace a more conscious and human way of consumption. We believe in a world where collaborative economy is mainstream. This is what drives us. 💫

Wallapop operates in Spain, Italy and Portugal, offering a catalogue of several hundreds of millions of products and services. Powered by technical innovation and continuous improvement, we bring together the scale & trust of classifieds with the marketplace’s convenience & reach. 🌱 Our mission is to enable a connected trade ecosystem, making 2nd-hand the norm through smart use of technology.

The Challenge 🧩 

Wallapop generates billions of data points daily. With a mature data infrastructure already in place, our Data Science and Machine Learning area is gaining significant momentum. As we scale, we face the exciting challenge of taking our ML Platform to the next level to support complex solutions in Personalization, Search, Trust & Safety, and Logistics. As a Senior ML Engineer, you will lead the evolution of our ML Platform and MLOps practice. You will partner with Data Scientists, Data Engineers, and DevOps to shape a vision that balances innovation with reliability, ensuring our models scale efficiently to serve millions of users.

What You Will Do 👇

• Iterate and maintain Wallapop’s ML Platform, identifying opportunities to improve speed, reliability, and maintainability. You will define the long-term vision and roadmap for MLOps.
• Work hand-in-hand with Data Scientists to support their efforts, ensuring they have the tooling to develop, deploy, and monitor scalable models efficiently.
• Define and promote engineering best practices (coding standards, testing, CI/CD) within the ML domain.
• Partner with Data Engineering and DevOps to align ML development with company-wide infrastructure and data governance standards.
• Investigate and integrate new frameworks and tools (e.g., for LLMs or real-time inference) to keep our stack modern and effective.

What We’re Looking For 🔎

• Proven experience building and owning production-ready ML platforms and pipelines. You understand the full lifecycle from experimentation to monitoring.
• Deep understanding of AWS components (SageMaker, Lambda, S3) and container orchestration with Kubernetes.
• Strong software engineering background with proficiency in Python, Git, and CI/CD workflows. You write robust, testable code.
• Experience with real-time ML architectures, leveraging tools like Kafka for low-latency ingestion and inference.
• Hands-on experience with vector databases or semantic search infrastructure (e.g., OpenSearch, Vertex AI), including indexing and retrieval tuning.
• Familiarity with the broader ML toolkit, such as orchestration/tracking tools (Flyte, MLFlow, Feast) and standard libraries (Pandas, Scikit-learn, TensorFlow/PyTorch).
• Professional proficiency in English, with the ability to explain complex technical concepts to diverse stakeholders.

What Would Be A Plus 🚀

• Hands-on experience working with LLMs, RAG architectures, and libraries like LangChain or LlamaIndex.
• Familiarity with Big Data technologies like Spark or Beam.
• Experience with Data Engineering tools such as Airflow, dbt, or Datahub.
• Experience with other cloud platforms like GCP or Azure in addition to AWS.

Do note that all our jobs are 📍 Barcelona based. We follow a hybrid model where flexibility rules. We commit to a minimum of 6 days per month in the office. Each team self-organizes to decide on cadence and in-person/remote rituals.

Wallapop is an equal opportunity employer. We celebrate diversity and are committed to creating an inclusive environment for all employees as we want Wallapop to be a place for everyone.

Additionally to the opportunity to contribute to an agile product set up and work together towards achieving our meaningful mission, we offer the following 🍭 Perks & Benefits:

• Generous individual learning budget of 2k per year
• Free office meals, lunch selection from different providers
• Group and individual English, Catalan & Spanish lessons as part of our working day
• Private Health Insurance with Alan
• Flexible working hours + intensive Fridays
• Flexible remuneration to deduct from gross salary (kindergarten/food/transport check)
• Gym & Wellness plan, including physiotherapist in the office
• Generous referral Program & Charity Donation
• Bonus for weddings & newborns
• Wallapop Renta (Tax income support)
• Monthly plan for free shipping, bumps & home-pick-up on our services
• Work anniversary Gifts and Birthday Surprises
• Contribution towards your WIFI in your monthly payroll
• One-off payment based on compensation package to go towards setting up your home office
• Relocation package (monetary support and legal advice) and visa sponsorship, if applicable
• 26 holidays per year
• TOP hardware of your choice (latest Apple or Windows)

What does the hiring process for this position look like? 👀 **Please, note that all interviews take place remotely over hangouts.**

• Intro Call - run by Talent Acquisition, focus on providing more information about the role and the company as well as going over your experience, motivation, and expectations. This usually takes 45-60 minutes.
• Technical Task - you will be assigned a challenge to assess the technical skills required for the role.
• Expertise Interview - run by the core team, focusing on the hard skills and the ability to deliver in a given context. This usually takes 60-90 minutes.
• Stakeholder Interview - run by the hiring team and relevant stakeholders, focus on the ability to collaborate & deliver in a cross-functional set-up. This usually takes 60 minutes.
• Culture-Add Interview - run by culture interviewers, focus on adherence to Wallapop's purpose and business proposition. This usually takes 60 minutes.
• Offer - should you be the right candidate, your offer will be discussed over a call with talent acquisition and will then be confirmed in writing.

Wallapop is a Barcelona based scale-up driven by the purpose to empower people to embrace a more conscious and human way of consumption. We believe in a world where collaborative economy is mainstream. This is what drives us. 💫

Wallapop operates in Spain, Italy and Portugal, offering a catalogue of several hundreds of millions of products and services. Powered by technical innovation and continuous improvement, we bring together the scale & trust of classifieds with the marketplace’s convenience & reach. 🌱 Our mission is to enable a connected trade ecosystem, making 2nd-hand the norm through smart use of technology.

The Challenge 🧩

Working on a 10+ year-old codebase used by millions, you will join a cross-functional team dedicated to creating impactful user experiences. Our core technology stack includes:

• Our own simplified, TCA-inspired architecture using RxSwift

• Custom dependency injection system

• Extensive testing infrastructure, including snapshot-based integration tests

• Modern UIKit and SwiftUI

• Performance monitoring and analytics tools

• Realm and CoreData

• Quick and Nimble

• Snapshot Testing

• Bazel-based build system

What You Will Do 👇

• Design and implement new features in alignment with our architectural guidelines.

• Collaborate with product and design teams to deliver high-quality user experiences.

• Write clean, maintainable, and testable code.

• Engage in code reviews and technical discussions to elevate team standards.

• Continuously improve our testing practices and overall code quality.

• Contribute to the evolution of our iOS architecture and development practices.

• Drive technical decisions that directly impact your team's feature development.

What We’re Looking For 🔎

• Strong experience with Swift and modern iOS development.

• A proven track record of writing clean, scalable, and maintainable code.

• Experience working in large, modular codebases within cross-functional agile teams.

• A strong product mindset with a passion for delivering excellent user experiences.

What Would Be A Plus 🚀 

• Experience with UI/UX polish, custom animations, and iOS accessibility standards.

• Solid understanding of reactive programming (RxSwift or Combine).

• Experience working on large-scale, high-traffic consumer applications.

• Familiarity with agentic engineering and AI coding assistants (e.g., Claude Code, GitHub Copilot).

Do note that all our jobs are 📍 Barcelona based. We follow a hybrid model where flexibility rules. We commit to a minimum of 6 days per month in the office. Each team self-organizes to decide on cadence and in-person/remote rituals.

Wallapop is an equal-opportunity employer. We celebrate diversity and are committed to creating an inclusive environment for all employees as we want Wallapop to be a place for everyone.

We sponsor visa processes for international candidates when applicable and provide legal & admin support along the process combined with a competitive relocation package.

Additionally to the opportunity to contribute to an agile product set up and work together towards achieving our meaningful mission, we offer the following 🍭 Perks & Benefits:

• Generous individual learning budget of 2k per year
• Free office meals, lunch selection from different providers
• Group and individual English, Catalan & Spanish lessons as part of our working day
• Private Health Insurance with Alan
• Flexible working hours + intensive Fridays
• Flexible remuneration to deduct from gross salary (kindergarten/food/transport check)
• Gym & Wellness plan, including physiotherapist in the office
• Generous referral Program & Charity Donation
• Bonus for weddings & newborns
• Wallapop Renta (Tax income support)
• Monthly plan for free shipping, bumps & home-pick-up on our services
• Work anniversary Gifts and Birthday Surprises
• Contribution towards your WIFI in your monthly payroll
• One-off payment based on compensation package to go towards setting up your home office
• Relocation package (monetary support and legal advice) and visa sponsorship, if applicable
• 26 holidays per year
• TOP hardware of your choice (latest Apple or Windows)

What does the hiring process for this position look like? 👀 **Please, note that all interviews take place remotely over hangouts.**

• Intro Call - run by Talent Acquisition, focus on providing more information about the role and the company as well as going over your experience, motivation, and expectations. This usually takes 45-60 minutes.
• Technical Task - you will be assigned a test that consists of a coding challenge to assess the technical skills required for the role. You will have up to 7 days to complete it. If you have a recent project that meets the same requirements, you can submit it instead.
• Expertise Interview - run by the core team, focusing on the hard skills and the ability to deliver in a given context. This usually takes 60-90 minutes.
• Stakeholder Interview - run by the hiring team and relevant stakeholders, focus on the ability to collaborate & deliver in a cross-functional set-up. This usually takes 60 minutes.
• Culture Interview - run by culture interviewers, focus on adherence to Wallapop's purpose and business proposition. This usually takes 60 minutes.
• Offer - should you be the right candidate, your offer will be discussed over a call with talent acquisition and will then be confirmed in writing.

Wallapop is a Barcelona based scale-up driven by the purpose to empower people to embrace a more conscious and human way of consumption. We believe in a world where collaborative economy is mainstream. This is what drives us. 💫

Wallapop operates in Spain, Italy and Portugal, offering a catalogue of several hundreds of millions of products and services. Powered by technical innovation and continuous improvement, we bring together the scale & trust of classifieds with the marketplace’s convenience & reach. 🌱 Our mission is to enable a connected trade ecosystem, making 2nd-hand the norm through smart use of technology.

The Challenge 🧩

You will join the Android Platform Team, the engine room that enables our mobile engineers to ship features to millions of users with speed and confidence. In a 10+ year-old codebase with 50+ modules, your mission is to eliminate friction and build the foundation of our mobile future.

What you will find:

• Developer Experience (DevEx) at Scale: You won’t just build features; you will build the tools, CI/CD pipelines, and architectures that other engineers use daily.
• Deep Tooling & Build Systems: We manage a complex modular environment where Gradle and CI/CD automation are at the heart of everything we do.
• System-Level Thinking: From optimizing build time to managing our Dagger/Anvil DI graph, you’ll tackle challenges that impact the entire Android Chapter.
• Data-Driven Infrastructure: We don't guess; we measure. You will use metrics to identify bottlenecks in the development lifecycle and prioritize what to fix next.

What You Will Do 👇

You’ll be the "Engineer for the Engineers," driving technical excellence across the organization. To do so, you will:

• Master the Build System: Maintain and optimize our Gradle configuration, plugins, and build logic to ensure fast and reliable builds.
• Optimize the Feedback Loop: Improve CI/CD pipelines and local iteration speed to ensure developers can test and deploy code faster.
• Own the Release Engine: Maintain and evolve our automated release process, ensuring that shipping to millions of users is a non-event.
• Standardize & Modernize: Help define the "Golden Path" for Android development, providing the modular architecture and patterns that teams need to succeed.
• Cross-Platform Collaboration: Work alongside iOS and Web Platform engineers to align on tooling, infrastructure, and DevOps culture.
• Infrastructure as Code: Manage and scale our cloud resources (using AWS when needed) to support our mobile infrastructure.

What We’re Looking For 🔎

• Android Enthusiast & Expert: Deep knowledge of the Android SDK and Kotlin. You don't just use libraries; you understand how the system works under the hood.
• Build System Mastery: Extensive experience with Gradle (writing custom plugins, optimizing build scripts, and understanding the configuration phase).
• The "Platform" Mindset: A passion for Developer Experience (DevEx)—you find joy in making your colleagues' lives easier and their builds faster.
• Performance & Stability: Experience using profilers and monitoring tools to debug complex issues like memory leaks, ANRs, or slow startup times.
• Modularization at Scale: Proven experience managing large-scale, multi-module projects and understanding the trade-offs of different architectural patterns.
• CI/CD & Automation: Solid experience with CI tools (GitHub Actions, Bitrise, etc.) and a pragmatic approach to automating the full release lifecycle.
• Polyglot Curiosity: Comfortable using Python for scripting and an interest in learning AWS infrastructure when needed.

What Would Be A Plus 🚀 

• Experience with Gradle Enterprise (Develocity) or writing custom Gradle plugins.
• Knowledge of Infrastructure as Code (IaC) or basic AWS management.
• Previous experience in a Developer Experience (DevEx) or Mobile Infra role.
• Experience managing Design Systems from an infrastructure perspective (theming engines, token automation).

Do note that all our jobs are 📍 Barcelona based. We follow a hybrid model where flexibility rules. We commit to a minimum of 6 days per month in the office. Each team self-organizes to decide on cadence and in-person/remote rituals.

Wallapop is an equal opportunity employer. We celebrate diversity and are committed to creating an inclusive environment for all employees as we want Wallapop to be a place for everyone.

We sponsor visa processes for international candidates when applicable and provide legal & admin support along the process combined with a competitive relocation package.

Additionally to the opportunity to contribute to an agile product set up and work together towards achieving our meaningful mission, we offer the following 🍭 Perks & Benefits:

• Generous individual learning budget of 2k per year
• Free office meals, lunch selection from different providers
• Group and individual English, Catalan & Spanish lessons as part of our working day
• Private Health Insurance with Alan
• Flexible working hours + short Fridays
• Flexible remuneration to deduct from gross salary (kindergarten/food/transport check)
• Gym & Wellness plan, including physiotherapist in the office
• Generous referral Program & Charity Donation
• Bonus for weddings & newborns
• Wallapop Renta (Tax income support)
• Monthly plan for free shipping, bumps & home-pick-up on our services
• Work anniversary Gifts and Birthday Surprises
• Contribution towards your WIFI in your monthly payroll
• One-off payment based on compensation package to go towards setting up your home office
• Relocation package (monetary support and legal advice) and visa sponsorship, if applicable
• 26 holidays per year
• TOP hardware of your choice (latest Apple or Windows)

What does the hiring process for this position look like? 👀 **Please, note that all interviews take place remotely over hangouts.**

• Intro Call - run by Talent Acquisition, focus on providing more information about the role and the company as well as going over your experience, motivation, and expectations. This usually takes 45-60 minutes.
• Technical Task - you will be assigned a test that consists of a coding challenge to assess the technical skills required for the role. You will have up to 7 days to complete it. If you have a recent project that meets the same requirements, you can submit it instead.
• Expertise Interview - run by the core team, focusing on the hard skills and the ability to deliver in a given context. This usually takes 60-90 minutes.
• Stakeholder Interview - run by the hiring team and relevant stakeholders, focus on the ability to collaborate & deliver in a cross-functional set-up. This usually takes 60 minutes.
• Culture Interview - run by culture interviewers, focus on adherence to Wallapop's purpose and business proposition. This usually takes 60 minutes.
• Offer - should you be the right candidate, your offer will be discussed over a call with talent acquisition and will then be confirmed in writing.

Join Proton and build a better internet where privacy is the default

Proton was founded in 2014 by scientists from CERN on a simple truth: privacy is a fundamental human right. Since then, we’ve built the world’s largest encrypted email service (Proton Mail) and expanded into Proton VPN, Proton Drive, Proton Pass, and Proton Calendar—tools used by millions globally to protect their freedom, fight censorship, and keep their data safe. In some situations, Proton has literally helped save lives!

We are profitable, independent (no VC control), and selectively hire from the top ~1% of applicants. Our 500+ team members across 50+ countries come from leading organizations and elite academic backgrounds. We move fast, keep hierarchy light, and prioritize impact over optics. If you want to do meaningful work with exceptionally high-caliber people, this is it. Join us and do work you can truly be proud of. Check our open-source projects here!

The Payments Team

The goal of the Payments team is to enable revenue generation for the entire Proton ecosystem. This comes in the form of introducing new payment methods for users to architecting our client libraries. This team has impact across all of Proton's products and is critical to the success of the business as a whole.

• As Proton is a global Company, the Payments Team works to continuously expand the possibilities for users to pay with various payment methods, beyond just plain credit cards or Paypal.
• The team works in tight collaboration with the Account Team (responsible for the Proton user lifecycle), the Proton Finance team, and every single Business Unit to ensure that plans, promotions and pricing meet user expectations.
• The mission of the team is to empower anyone in the world who wish to use Proton services, to become a Proton subscriber by building enticing interfaces, being able to progressively reach global markets, by providing the methods and tooling allowing users to pay, and for the Proton organization to properly being able to measure growth, and to follow the relative financial regulations

Tech Stack and Tools:

• Differently than many other stacks at Proton, the Payments stack depends largely on external services such as payment providers, tax-information providers, currency-conversion providers... As such it is critical, for the success of the service, to build with resilience.
• Internally our backend code is in general based on PHP/Symfony, our frontend is based on React, our mobile code is based on Kotlin (on Android) and on Swift (on iOS), with a growing shared codebase in Rust.
• All our client-code is open-source and GPL3.
• We are migrating our infrastructure to Kubernetes.
• Everything runs on premise in Proton's data-centers.
• To organize our work we use classic tools such as Jira and Confluence.

Future Plans:

• With payments being the backbone of any subscription business, we have ambitious plans to expand the team to cover a wide breadth of topics ranging from demystifying payment performance data across regions/products, to thinking about the holistic strategy of product catalogs, and everything in between. This particular team requires someone who is a strong generalist, who thrives with ambiguity. There's huge potential for growth no matter the domain, and the outcome for any candidate is an in-depth view into how money moves globally.

What you will do:

• Build features in all of Proton's products.
• Close interactions with products and engineers across the company.
• Build scalable software architecture through software engineering best practices.
• Optimise user experience and design.

Job requirements:

• Proven experience with back-end development 
• Expertise in building scalable, high-performance solutions
• Proficiency with profiling techniques and performance optimization tools
• Experience leading a team initiative from discovery to production
• Strong understanding of SQL (MySQL preferred) and data modeling best practices
• Familiarity with Redis or other caching technologies for performance optimization
• Knowledge of security best practices and experience implementing secure software solutions
• In-depth understanding of HTTP/REST, including both the development and consumption of web-based APIs
• Solid grasp of cryptographic concepts, including key exchange, and the distinction between symmetric and asymmetric encryption

Bonus points for: 

• Experience within the payments domain

Even if you don’t meet all the requirements listed above, but feel you could still be a great fit, please still apply.

What We Offer

• Work that Matters: millions of people trust Proton with their privacy. We answer only to our users — not advertisers, not investors with conflicting agendas, not governments. The work you do here is real, and the impact is measurable. (read more about our impact here)
• Work with smart and dedicated people - Our team is diverse, collaborative, and tight-knit with people coming from all walks of life, including many of the world’s top academic institutions and organizations, such as MIT, Harvard, Stanford, Caltech, Cambridge, and ETH.
• Technology: you'll get the right hardware and the right software you need to do your best work.
• Learning & Development: we invest in your growth because sharp people make us better. Proton is one of the fastest ways to accelerate your career because you'll be thrown into real challenges, with real ownership, from day one.
• Employee Benefits: your wellbeing isn't an afterthought. We offer strong health coverage, solid retirement options, generous leave, and wellness support so you can bring your best self to work every day
• Stock Options: at Proton, we all have the opportunity to be owners of the company. From day one, you have a real stake in what we're building. When Proton wins, you win.
• In-Person Collaboration: Amazing things happen when passionate, smart, and purposeful people get together in the same room. With offices across Geneva, Zürich, Barcelona, London and more, you'll spend most of your time collaborating face-to-face with people who genuinely care about what they're building
• Food: Lunch and snacks are on us every day in our offices so you can focus on the work and not on what's for lunch.
• Transport: getting to the office shouldn't cost you. We cover public transport, bike allowances, or parking, whichever works for you.
• Flexible Working: you own your schedule. Set hours that work for you and your team — because outcomes matter more than when the clock says you started.

Our Commitment to Diversity and Inclusion

At Proton, we believe diversity drives innovation and strengthens our mission to provide privacy as a default for all. We are committed to fostering an inclusive environment where all individuals, regardless of race, ethnicity, gender, age, sexual orientation, physical ability, or socio-economic background, feel valued and empowered. We strive to create equal opportunities, promote open dialogue, and support continuous learning to ensure every voice is heard and respected.

If you need any extra support or reasonable adjustments during the hiring process, please let your talent partner know.

Candidate Privacy Notice

When you apply for a position, refer a candidate, or are considered for a role at Proton Technologies AG (Proton, we, us, or our), your information is stored in Greenhouse, in accordance with their Service Privacy Policy. This information is used to evaluate your suitability for the posted position. We also retain this information for consideration for future roles that you may apply for or that we believe may align with your background and skills.

If we no longer have a legitimate business need to process your information, we will either delete or anonymize it. Should you have any inquiries about how we use or manage your information, or if you wish to access, correct, or delete your data, please contact our privacy team at careers@proton.ch.

Proton does not accept unsolicited resumes from any sources other than directly from candidates. We will not pay a fee for any placement resulting from an unsolicited offer, even if the candidate is subsequently hired by Proton.

To learn more about our privacy policy, please visit our privacy policy page.

#LI-ONSITE

About Proton

Join Proton and build a better internet where privacy is the default

Proton was founded in 2014 by scientists from CERN on a simple truth: privacy is a fundamental human right. Since then, we’ve built the world’s largest encrypted email service (Proton Mail) and expanded into Proton VPN, Proton Drive, Proton Pass, and Proton Calendar—tools used by millions globally to protect their freedom, fight censorship, and keep their data safe. In some situations, Proton has literally helped save lives!

We are profitable, independent (no VC control), and selectively hire from the top ~1% of applicants. Our 500+ team members across 50+ countries come from leading organizations and elite academic backgrounds. We move fast, keep hierarchy light, and prioritize impact over optics. If you want to do meaningful work with exceptionally high-caliber people, this is it. Join us and do work you can truly be proud of. Check our open-source projects here!

The team:

We're a tight-knit, passionate Android engineering team building privacy-first apps that are trusted by millions of people around the world — and yes, our code is open source, so your work is truly out there making a difference. We move fast, skip the bureaucracy, and genuinely care about what we ship. Whether you're deep in Espresso tests or debating architecture over lunch, you'll be surrounded by people who are as excited about quality as you are. If you love Android, hate flaky tests, and want your work to actually matter — you'll fit right in.

Tech Stack and Tools:

Kotlin, Java, Espresso, UI Automator, Maestro

What you will do:

• Design, develop, and maintain automated test frameworks and pipelines for Proton's Android applications

• Write and execute UI, functional, integration, and end-to-end test suites using modern Android testing tools and best practices

• Work hand-in-hand with Android developers to define testability requirements and embed automated tests into CI/CD workflows

• Hunt down bugs, document them clearly, and collaborate with the team to get them fixed fast

• Perform exploratory and risk-based testing with a sharp eye on privacy, data integrity, and security behavior

• Own and evolve the Android test infrastructure, including emulator farms, device labs, and test environment configurations

• Dig into test results, spot patterns, and turn findings into actionable improvements that raise the quality bar

• Champion QA best practices across the team and help shape how we think about quality at every stage of development

• Review test code with the same rigor as production code — maintainability and scalability matter here

• Keep up with the Android ecosystem, new testing frameworks, and open-source tooling so we're always ahead of the curve

What we are looking for:

• 3–5 years of hands-on experience in Android test automation, ideally on consumer-facing apps with a large user base

• Strong proficiency in Kotlin and/or Java, with solid experience writing clean, maintainable test code

• Proven experience with Android testing frameworks such as Espresso, UI Automator, or Maestro

• Good understanding of CI/CD pipelines and experience integrating Android tests with tools like GitLab CI, GitHub Actions, or similar

• Familiarity with Android emulators, physical device testing, and cloud-based device farms (e.g., Firebase Test Lab)

• Comfortable navigating Android Studio, ADB, and the broader Android development toolchain

• Experience with version control using Git, and a natural fit in an open-source collaborative workflow

• A good nose for security and privacy issues — understanding of privacy-by-design is a real plus

• Ability to read and understand application source code to sharpen test coverage and catch edge cases early

• Sharp analytical mindset with a structured, detail-oriented approach — you don't let things slip through the cracks

• Great communicator who thrives in a remote-friendly, internationally distributed team

• Genuine enthusiasm for open-source software, Android, and building technology that protects people's privacy

What We Offer:

• Work that Matters: millions of people trust Proton with their privacy. We answer only to our users — not advertisers, not investors with conflicting agendas, not governments. The work you do here is real, and the impact is measurable. (read more about our impact here)

• Stock Options: at Proton, we all have the opportunity to be owners of the company. From day one, you have a real stake in what we're building. When Proton wins, you win.

• Technology: you'll get the right hardware and the right software you need to do your best work.

• Learning & Development: we invest in your growth because sharp people make us better. Proton is one of the fastest ways to accelerate your career because you'll be thrown into real challenges, with real ownership, from day one.

• Employee Benefits: your wellbeing isn't an afterthought. We offer strong health coverage, solid retirement options, generous leave, and wellness support so you can bring your best self to work every day

• In-Person Collaboration: Amazing things happen when passionate, smart, and purposeful people get together in the same room. With offices across Geneva, Zürich, Barcelona, London and more, you'll spend most of your time collaborating face-to-face with people who genuinely care about what they're building

• Food: Lunch and snacks are on us every day in our offices so you can focus on the work and not on what's for lunch.

• Transport: getting to the office shouldn't cost you. We cover public transport, bike allowances, or parking, whichever works for you.

• Flexible Working: you own your schedule. Set hours that work for you and your team — because outcomes matter more than when the clock says you started.

Our Commitment to Diversity and Inclusion

At Proton, we believe diversity drives innovation and strengthens our mission to provide privacy as a default for all. We are committed to fostering an inclusive environment where all individuals, regardless of race, ethnicity, gender, age, sexual orientation, physical ability, or socio-economic background, feel valued and empowered. We strive to create equal opportunities, promote open dialogue, and support continuous learning to ensure every voice is heard and respected.

If you need any extra support or reasonable adjustments during the hiring process, please let your talent partner know.

Candidate Privacy Notice

When you apply for a position, refer a candidate, or are considered for a role at Proton Technologies AG (Proton, we, us, or our), your information is stored in Greenhouse, in accordance with their Service Privacy Policy. This information is used to evaluate your suitability for the posted position. We also retain this information for consideration for future roles that you may apply for or that we believe may align with your background and skills.

If we no longer have a legitimate business need to process your information, we will either delete or anonymize it. Should you have any inquiries about how we use or manage your information, or if you wish to access, correct, or delete your data, please contact our privacy team at careers@proton.ch.

Proton does not accept unsolicited resumes from any sources other than directly from candidates. We will not pay a fee for any placement resulting from an unsolicited offer, even if the candidate is subsequently hired by Proton.

To learn more about our privacy policy, please visit our privacy policy page.

Salary range (Vilnius) - 48.800 - 54.200 EUR gross annual 

#LI-Onsite

Join Proton and build a better internet where privacy is the default

Proton was founded in 2014 by scientists from CERN on a simple truth: privacy is a fundamental human right. Since then, we’ve built the world’s largest encrypted email service (Proton Mail) and expanded into Proton VPN, Proton Drive, Proton Pass, and Proton Calendar—tools used by millions globally to protect their freedom, fight censorship, and keep their data safe. In some situations, Proton has literally helped save lives!

We are profitable, independent (no VC control), and selectively hire from the top ~1% of applicants. Our 500+ team members across 50+ countries come from leading organizations and elite academic backgrounds. We move fast, keep hierarchy light, and prioritize impact over optics. If you want to do meaningful work with exceptionally high-caliber people, this is it. Join us and do work you can truly be proud of. Check our open-source projects here!

The team:

Purpose of the role:  

We are seeking a skilled and experienced Test Engineer to join our distributed team. As a Test Engineer, you will be responsible for ensuring the quality and reliability of Proton Pass product for Android, iOS and Web platforms. You will play a crucial role in establishing QA processes and contributing to the release of our product every few weeks. This is an independent contributor role that requires a strong understanding of multi-platform testing and a passion for delivering high-quality software.

What you will do: 

• Collaborate closely with the product team, including developers, product managers, and designers, as an embedded member.
• Focus on continuously improving the quality of our product.
• Participate actively in reviewing feature specifications and wireframes.
• Work alongside the Product Owner to ensure testable acceptance criteria.
• Develop and maintain comprehensive test cases while having a strong understanding of product functionality.
• Identify and diligently track quality issues, reporting clear and accurate bug reports.
• Engage in team activities such as weekly meetings and reviews of designs and specifications.
• Promote and adhere to quality best practices to ensure high-quality deliverables.

Job requirements: 

• Professional experiences working on Web and at least a mobile platform (Android or iOS)
• Proficiency in manual, including the creation and review of test plans and cases.
• Good capacity in prioritization
• Ability to conduct thorough tests to identify and prevent issues before software changes go live.
• Strong understanding of quality assurance methodologies, tools, and processes.
• Independent and highly motivated problem solver.
• Enthusiasm for innovation, learning new concepts, and sharing ideas.
• Previous work experience in an agile or scrum framework.

Bonus points for:

• Having interest in privacy & security softwares
• Having a good understanding of using a password manager
• Being up to date with the latest evolution in technology 
• Automation QA 

What We Offer

• Work that Matters: millions of people trust Proton with their privacy. We answer only to our users — not advertisers, not investors with conflicting agendas, not governments. The work you do here is real, and the impact is measurable. (read more about our impact here)
• Work with smart and dedicated people - Our team is diverse, collaborative, and tight-knit with people coming from all walks of life, including many of the world’s top academic institutions and organizations, such as MIT, Harvard, Stanford, Caltech, Cambridge, and ETH.
• Technology: you'll get the right hardware and the right software you need to do your best work.
• Learning & Development: we invest in your growth because sharp people make us better. Proton is one of the fastest ways to accelerate your career because you'll be thrown into real challenges, with real ownership, from day one.
• Employee Benefits: your wellbeing isn't an afterthought. We offer strong health coverage, solid retirement options, generous leave, and wellness support so you can bring your best self to work every day
• Stock Options: at Proton, we all have the opportunity to be owners of the company. From day one, you have a real stake in what we're building. When Proton wins, you win.
• In-Person Collaboration: Amazing things happen when passionate, smart, and purposeful people get together in the same room. With offices across Geneva, Zürich, Barcelona, London and more, you'll spend most of your time collaborating face-to-face with people who genuinely care about what they're building
• Food: Lunch and snacks are on us every day in our offices so you can focus on the work and not on what's for lunch.
• Transport: getting to the office shouldn't cost you. We cover public transport, bike allowances, or parking, whichever works for you.
• Flexible Working: you own your schedule. Set hours that work for you and your team — because outcomes matter more than when the clock says you started.

Our Commitment to Diversity and Inclusion

At Proton, we believe diversity drives innovation and strengthens our mission to provide privacy as a default for all. We are committed to fostering an inclusive environment where all individuals, regardless of race, ethnicity, gender, age, sexual orientation, physical ability, or socio-economic background, feel valued and empowered. We strive to create equal opportunities, promote open dialogue, and support continuous learning to ensure every voice is heard and respected.

If you need any extra support or reasonable adjustments during the hiring process, please let your talent partner know.

Candidate Privacy Notice

When you apply for a position, refer a candidate, or are considered for a role at Proton Technologies AG (Proton, we, us, or our), your information is stored in Greenhouse, in accordance with their Service Privacy Policy. This information is used to evaluate your suitability for the posted position. We also retain this information for consideration for future roles that you may apply for or that we believe may align with your background and skills.

If we no longer have a legitimate business need to process your information, we will either delete or anonymize it. Should you have any inquiries about how we use or manage your information, or if you wish to access, correct, or delete your data, please contact our privacy team at careers@proton.ch.

Proton does not accept unsolicited resumes from any sources other than directly from candidates. We will not pay a fee for any placement resulting from an unsolicited offer, even if the candidate is subsequently hired by Proton.

To learn more about our privacy policy, please visit our privacy policy page.

#LI-Onsite

About Proton

Join Proton and build a better internet where privacy is the default

Proton was founded in 2014 by scientists from CERN on a simple truth: privacy is a fundamental human right. Since then, we’ve built the world’s largest encrypted email service (Proton Mail) and expanded into Proton VPN, Proton Drive, Proton Pass, and Proton Calendar—tools used by millions globally to protect their freedom, fight censorship, and keep their data safe. In some situations, Proton has literally helped save lives!

We are profitable, independent (no VC control), and selectively hire from the top ~1% of applicants. Our 500+ team members across 50+ countries come from leading organizations and elite academic backgrounds. We move fast, keep hierarchy light, and prioritize impact over optics. If you want to do meaningful work with exceptionally high-caliber people, this is it. Join us and do work you can truly be proud of. Check our open-source projects here!

The team:

ProtonVPN runs on a distributed architecture of Linux servers and a set of apps available on each major platform (Windows, Android, iOS, macOS, and Linux) that interact with our infrastructure.

As a member of the ProtonVPN Research and Development team, you will work on maintaining the security of ProtonVPN’s infrastructure, improving its overall performance, designing and implementing new features. On any given day, you might code in C or Rust, script in Python or Lua, create patches for the Linux kernel, or debug system-level issues on different operating systems. You will work in close collaboration with the entire ProtonVPN development team on any outstanding projects. You will face unique and varied challenges that will require continuous  learning.

What you will do:

• Being an active member of the ProtonVPN R&D team

• Collaborating with app developers to help solve the various complex challenges related to (but not limited to) the networking stack of Linux, macOS, iOS, Android, and Windows systems

• Helping develop innovative solutions to improve the connectivity, stability, performance, scalability, security, and resilience of ProtonVPN’s infrastructure and client software, and extend their functionality

• Contributing to existing open-source projects or creating new ones

What we are looking for:

• Expert-level knowledge of operating system internals

• Expertise with network protocols and implementation

• A documented track record of contributions to system-level projects and applications

• Experience with software development

• Understanding of the principles of quality assurance

Bonus points for: 

• Expertise in Windows, macOS, or Linux system development

• Extensive experience working with Linux kernel, Windows drivers, or macOS system extensions development

• Strong understanding of system programming languages (C/C++, Rust, Go, Python, etc.)

• Experience with debugging code and code profiling

• Good understanding of TCP/IP protocol and settings (e.g., congestion algorithms)

• Strong understanding of VPN protocols (particularly OpenVPN and WireGuard)

• Experience with cryptography concepts (e.g., TLS certificates and public key infrastructure)

What We Offer:

• Work that Matters: millions of people trust Proton with their privacy. We answer only to our users — not advertisers, not investors with conflicting agendas, not governments. The work you do here is real, and the impact is measurable. (read more about our impact here)

• Stock Options: at Proton, we all have the opportunity to be owners of the company. From day one, you have a real stake in what we're building. When Proton wins, you win.

• Technology: you'll get the right hardware and the right software you need to do your best work.

• Learning & Development: we invest in your growth because sharp people make us better. Proton is one of the fastest ways to accelerate your career because you'll be thrown into real challenges, with real ownership, from day one.

• Employee Benefits: your wellbeing isn't an afterthought. We offer strong health coverage, solid retirement options, generous leave, and wellness support so you can bring your best self to work every day

• In-Person Collaboration: Amazing things happen when passionate, smart, and purposeful people get together in the same room. With offices across Geneva, Zürich, Barcelona, London and more, you'll spend most of your time collaborating face-to-face with people who genuinely care about what they're building

• Food: Lunch and snacks are on us every day in our offices so you can focus on the work and not on what's for lunch.

• Transport: getting to the office shouldn't cost you. We cover public transport, bike allowances, or parking, whichever works for you.

• Flexible Working: you own your schedule. Set hours that work for you and your team — because outcomes matter more than when the clock says you started.

Our Commitment to Diversity and Inclusion

At Proton, we believe diversity drives innovation and strengthens our mission to provide privacy as a default for all. We are committed to fostering an inclusive environment where all individuals, regardless of race, ethnicity, gender, age, sexual orientation, physical ability, or socio-economic background, feel valued and empowered. We strive to create equal opportunities, promote open dialogue, and support continuous learning to ensure every voice is heard and respected.

If you need any extra support or reasonable adjustments during the hiring process, please let your talent partner know.

Candidate Privacy Notice

When you apply for a position, refer a candidate, or are considered for a role at Proton Technologies AG (Proton, we, us, or our), your information is stored in Greenhouse, in accordance with their Service Privacy Policy. This information is used to evaluate your suitability for the posted position. We also retain this information for consideration for future roles that you may apply for or that we believe may align with your background and skills.

If we no longer have a legitimate business need to process your information, we will either delete or anonymize it. Should you have any inquiries about how we use or manage your information, or if you wish to access, correct, or delete your data, please contact our privacy team at careers@proton.ch.

Proton does not accept unsolicited resumes from any sources other than directly from candidates. We will not pay a fee for any placement resulting from an unsolicited offer, even if the candidate is subsequently hired by Proton.

To learn more about our privacy policy, please visit our privacy policy page.

#LI-Onsite

Join Proton and build a better internet where privacy is the default

Proton was founded in 2014 by scientists from CERN on a simple truth: privacy is a fundamental human right. Since then, we’ve built the world’s largest encrypted email service (Proton Mail) and expanded into Proton VPN, Proton Drive, Proton Pass, and Proton Calendar—tools used by millions globally to protect their freedom, fight censorship, and keep their data safe. In some situations, Proton has literally helped save lives!

We are profitable, independent (no VC control), and selectively hire from the top ~1% of applicants. Our 500+ team members across 50+ countries come from leading organizations and elite academic backgrounds. We move fast, keep hierarchy light, and prioritize impact over optics. If you want to do meaningful work with exceptionally high-caliber people, this is it. Join us and do work you can truly be proud of. Check our open-source projects here!

The Payments Team

The goal of the Payments team is to enable revenue generation for the entire Proton ecosystem. This comes in the form of introducing new payment methods for users to architecting our client libraries. This team has impact across all of Proton's products and is critical to the success of the business as a whole.

• As Proton is a global Company, the Payments Team works to continuously expand the possibilities for users to pay with various payment methods, beyond just plain credit cards or Paypal.
• The team works in tight collaboration with the Account Team (responsible for the Proton user lifecycle), the Proton Finance team, and every single Business Unit to ensure that plans, promotions and pricing meet user expectations.
• The mission of the team is to empower anyone in the world who wish to use Proton services, to become a Proton subscriber by building enticing interfaces, being able to progressively reach global markets, by providing the methods and tooling allowing users to pay, and for the Proton organization to properly being able to measure growth, and to follow the relative financial regulations

Tech Stack and Tools:

• Differently than many other stacks at Proton, the Payments stack depends largely on external services such as payment providers, tax-information providers, currency-conversion providers... As such it is critical, for the success of the service, to build with resilience.
• Internally our backend code is in general based on PHP/Symfony, our frontend is based on React, our mobile code is based on Kotlin (on Android) and on Swift (on iOS), with a growing shared codebase in Rust.
• All our client-code is open-source and GPL3.
• We are migrating our infrastructure to Kubernetes.
• Everything runs on premise in Proton's data-centers.
• To organize our work we use classic tools such as Jira and Confluence.

Future Plans:

• With payments being the backbone of any subscription business, we have ambitious plans to expand the team to cover a wide breadth of topics ranging from demystifying payment performance data across regions/products, to thinking about the holistic strategy of product catalogs, and everything in between. This particular team requires someone who is a strong generalist, who thrives with ambiguity. There's huge potential for growth no matter the domain, and the outcome for any candidate is an in-depth view into how money moves globally.

What you will do:

• Build features in all of Proton's products.
• Close interactions with products and engineers across the company.
• Build scalable software architecture through software engineering best practices.
• Optimise user experience and design.

Job requirements:

• Proven experience with back-end development 
• Expertise in building scalable, high-performance solutions
• Proficiency with profiling techniques and performance optimization tools
• Experience leading a team initiative from discovery to production
• Strong understanding of SQL (MySQL preferred) and data modeling best practices
• Familiarity with Redis or other caching technologies for performance optimization
• Knowledge of security best practices and experience implementing secure software solutions
• In-depth understanding of HTTP/REST, including both the development and consumption of web-based APIs
• Solid grasp of cryptographic concepts, including key exchange, and the distinction between symmetric and asymmetric encryption

Bonus points for: 

• Experience within the payments domain

Even if you don’t meet all the requirements listed above, but feel you could still be a great fit, please still apply.

What We Offer

• Work that Matters: millions of people trust Proton with their privacy. We answer only to our users — not advertisers, not investors with conflicting agendas, not governments. The work you do here is real, and the impact is measurable. (read more about our impact here)
• Work with smart and dedicated people - Our team is diverse, collaborative, and tight-knit with people coming from all walks of life, including many of the world’s top academic institutions and organizations, such as MIT, Harvard, Stanford, Caltech, Cambridge, and ETH.
• Technology: you'll get the right hardware and the right software you need to do your best work.
• Learning & Development: we invest in your growth because sharp people make us better. Proton is one of the fastest ways to accelerate your career because you'll be thrown into real challenges, with real ownership, from day one.
• Employee Benefits: your wellbeing isn't an afterthought. We offer strong health coverage, solid retirement options, generous leave, and wellness support so you can bring your best self to work every day
• Stock Options: at Proton, we all have the opportunity to be owners of the company. From day one, you have a real stake in what we're building. When Proton wins, you win.
• In-Person Collaboration: Amazing things happen when passionate, smart, and purposeful people get together in the same room. With offices across Geneva, Zürich, Barcelona, London and more, you'll spend most of your time collaborating face-to-face with people who genuinely care about what they're building
• Food: Lunch and snacks are on us every day in our offices so you can focus on the work and not on what's for lunch.
• Transport: getting to the office shouldn't cost you. We cover public transport, bike allowances, or parking, whichever works for you.
• Flexible Working: you own your schedule. Set hours that work for you and your team — because outcomes matter more than when the clock says you started.

Our Commitment to Diversity and Inclusion

At Proton, we believe diversity drives innovation and strengthens our mission to provide privacy as a default for all. We are committed to fostering an inclusive environment where all individuals, regardless of race, ethnicity, gender, age, sexual orientation, physical ability, or socio-economic background, feel valued and empowered. We strive to create equal opportunities, promote open dialogue, and support continuous learning to ensure every voice is heard and respected.

If you need any extra support or reasonable adjustments during the hiring process, please let your talent partner know.

Candidate Privacy Notice

When you apply for a position, refer a candidate, or are considered for a role at Proton Technologies AG (Proton, we, us, or our), your information is stored in Greenhouse, in accordance with their Service Privacy Policy. This information is used to evaluate your suitability for the posted position. We also retain this information for consideration for future roles that you may apply for or that we believe may align with your background and skills.

If we no longer have a legitimate business need to process your information, we will either delete or anonymize it. Should you have any inquiries about how we use or manage your information, or if you wish to access, correct, or delete your data, please contact our privacy team at careers@proton.ch.

Proton does not accept unsolicited resumes from any sources other than directly from candidates. We will not pay a fee for any placement resulting from an unsolicited offer, even if the candidate is subsequently hired by Proton.

To learn more about our privacy policy, please visit our privacy policy page.

#LI-ONSITE

Join Proton and build a better internet where privacy is the default

Proton was founded in 2014 by scientists from CERN on a simple truth: privacy is a fundamental human right. Since then, we’ve built the world’s largest encrypted email service (Proton Mail) and expanded into Proton VPN, Proton Drive, Proton Pass, and Proton Calendar—tools used by millions globally to protect their freedom, fight censorship, and keep their data safe. In some situations, Proton has literally helped save lives!

We are profitable, independent (no VC control), and selectively hire from the top ~1% of applicants. Our 500+ team members across 50+ countries come from leading organizations and elite academic backgrounds. We move fast, keep hierarchy light, and prioritize impact over optics. If you want to do meaningful work with exceptionally high-caliber people, this is it. Join us and do work you can truly be proud of. Check our open-source projects here!

The Pass Team

Proton Pass is a secure, open-source password manager developed by Proton—the team behind Proton Mail and Proton VPN. Built with end-to-end encryption and a strong commitment to privacy, Proton Pass helps individuals and teams safely manage passwords, 2FA codes, notes, and more. As part of the Proton ecosystem, it integrates seamlessly with other privacy-first tools, ensuring robust protection for your digital identity.

What you will do:

We're seeking an experienced developer working across multiple web platforms including browser extensions, web and desktop applications. This role requires both front-end expertise and deep technical knowledge of browser internals, extension APIs, and desktop application frameworks

• Develop new features: Developing, deploying and supporting high-quality user experiences, including feature development and implementation.
• Collaboration: Work closely with backend, product owners, designers, QA, and other engineers to take initiatives from ideation to completion. Break down large initiatives into smaller milestones to gather stakeholder feedback quickly.
• Code review and optimization: Conduct code reviews and provide constructive feedback to ensure code quality, maintainability, and performance optimization.
• Testing: Develop and implement comprehensive testing strategies, including unit tests and end-to-end testing tests, to ensure the reliability of the Proton Pass product.

Job Requirements:

• Proven front-end expertise with deep technical knowledge of browser internals, extension APIs, and desktop application frameworks.
• Deep understanding of the Javascript ecosystem.
• Proficiency with TypeScript or type-safe programming paradigms.
• Strong understanding of software engineering best practices, Design patterns, CI/CD.
• A product mindset with a focus on offering the best user experiences.
• Experience working in a distributed team.

Bonus points for: 

• Experience with modern MV3 browser extension development.
• Experience with Electron or similar desktop application frameworks.
• Experience with browser extensions and/or cross-platform web applications.
• Experience working with service-worker architectures.
• Experience with WebAssembly and/or Rust.
• Experience with breaking down product requirements into architecture design and implementation.
• Experience with event-driven systems.
• Familiarity with UX, accessibility and localization concerns.
• Experience with application monitoring strategies.
• High-level understanding of cryptography concepts such as key exchange and the difference between symmetric and asymmetric encryption.

What We Offer:

• Work that Matters: millions of people trust Proton with their privacy. We answer only to our users — not advertisers, not investors with conflicting agendas, not governments. The work you do here is real, and the impact is measurable. (read more about our impact here)
• A great Team: Our team is diverse, collaborative, and tight-knit with people coming from all walks of life, including many of the world’s top academic institutions and organizations, such as MIT, Harvard, Stanford, Caltech, Cambridge, and ETH.
• Technology: you'll get the right hardware and the right software you need to do your best work.
• Learning & Development: we invest in your growth because sharp people make us better. Proton is one of the fastest ways to accelerate your career because you'll be thrown into real challenges, with real ownership, from day one.
• Employee Benefits: your wellbeing isn't an afterthought. We offer strong health coverage, solid retirement options, generous leave, and wellness support so you can bring your best self to work every day
• Stock Options: at Proton, we all have the opportunity to be owners of the company. From day one, you have a real stake in what we're building. When Proton wins, you win.
• In-Person Collaboration: Amazing things happen when passionate, smart, and purposeful people get together in the same room. With offices across Geneva, Zürich, Barcelona, London and more, you'll spend most of your time collaborating face-to-face with people who genuinely care about what they're building
• Food: Lunch and snacks are on us every day in our offices so you can focus on the work and not on what's for lunch.
• Transport: getting to the office shouldn't cost you. We cover public transport, bike allowances, or parking, whichever works for you.
• Flexible Working: you own your schedule. Set hours that work for you and your team — because outcomes matter more than when the clock says you started.

Our Commitment to Diversity and Inclusion

At Proton, we believe diversity drives innovation and strengthens our mission to provide privacy as a default for all. We are committed to fostering an inclusive environment where all individuals, regardless of race, ethnicity, gender, age, sexual orientation, physical ability, or socio-economic background, feel valued and empowered. We strive to create equal opportunities, promote open dialogue, and support continuous learning to ensure every voice is heard and respected.

If you need any extra support or reasonable adjustments during the hiring process, please let your talent partner know.

Candidate Privacy Notice

When you apply for a position, refer a candidate, or are considered for a role at Proton Technologies AG (Proton, we, us, or our), your information is stored in Greenhouse, in accordance with their Service Privacy Policy. This information is used to evaluate your suitability for the posted position. We also retain this information for consideration for future roles that you may apply for or that we believe may align with your background and skills.

If we no longer have a legitimate business need to process your information, we will either delete or anonymize it. Should you have any inquiries about how we use or manage your information, or if you wish to access, correct, or delete your data, please contact our privacy team at careers@proton.ch.

Proton does not accept unsolicited resumes from any sources other than directly from candidates. We will not pay a fee for any placement resulting from an unsolicited offer, even if the candidate is subsequently hired by Proton.

To learn more about our privacy policy, please visit our privacy policy page.

#LI-ONSITE

Join Proton and build a better internet where privacy is the default

Proton was founded in 2014 by scientists from CERN on a simple truth: privacy is a fundamental human right. Since then, we’ve built the world’s largest encrypted email service (Proton Mail) and expanded into Proton VPN, Proton Drive, Proton Pass, and Proton Calendar—tools used by millions globally to protect their freedom, fight censorship, and keep their data safe. In some situations, Proton has literally helped save lives!

We are profitable, independent (no VC control), and selectively hire from the top ~1% of applicants. Our 500+ team members across 50+ countries come from leading organizations and elite academic backgrounds. We move fast, keep hierarchy light, and prioritize impact over optics. If you want to do meaningful work with exceptionally high-caliber people, this is it. Join us and do work you can truly be proud of. Check our open-source projects here!

Purpose of the role:  

At ProtonVPN, we're on a mission to provide secure, private internet access to everyone—even in the most restrictive environments. Our infrastructure spans thousands of servers worldwide, operating on a distributed architecture that connects our suite of applications across platforms.

As a Systems and Reliability Engineer on the VPN Infrastructure team, among several areas, you'll be at the forefront of our battle against censorship regimes worldwide. You'll help design, implement, and maintain the robust systems that keep our users connected when they need privacy and security most.

What you will do:

• Infrastructure Management: Oversee and optimize our rapidly expanding global network of thousands of servers
• Automation & Reliability: Design and implement automation systems that ensure 99.95%+ uptime across our infrastructure
• Problem Solving: Serve as an active member of the on-call rotation, troubleshooting complex technical challenges across different network environments and censorship scenarios
• Monitoring Excellence: Develop and enhance sophisticated monitoring and alerting systems that provide real-time visibility into our global infrastructure
• Technical Implementation: Engineer solutions to improve connectivity, stability, performance, scalability, security, and resilience—particularly in adversarial network environments

Job requirements:

• Linux Expertise: Knowledge of Debian/Linux operating system internals, including NFtables, networking stack, and kernel tuning
• Infrastructure as Code: Experience with orchestration and automation using Ansible or similar tools
• Programming Skills: Python proficiency for developing automation tools and operational scripts
• Observability Tools: Hands-on experience with monitoring solutions like VictoriaMetrics and Grafana dashboards
• Security Knowledge: Understanding of security principles and best practices for infrastructure

What We Value:

• Strong problem-solving abilities, especially in high-pressure situations
• Adaptability and willingness to learn new technologies as our infrastructure evolves
• Collaborative mindset for working with the VPN R&D Team and Procurement on infrastructure initiatives
• Innovative thinking to address challenges in censorship-heavy environments

Bonus points for:

• Understanding of UDP and TCP/IP protocols, including troubleshooting and optimization techniques
• Experience implementing and troubleshooting VPN protocols, particularly OpenVPN and WireGuard
• Working knowledge of cryptography concepts, including TLS certificates and public key infrastructure (PKI)
• Experience with high-availability systems and resilient architecture design
• Background in fighting network censorship or working in restricted internet environments

What We Offer:

• Work that Matters: millions of people trust Proton with their privacy. We answer only to our users — not advertisers, not investors with conflicting agendas, not governments. The work you do here is real, and the impact is measurable. (read more about our impact here)
• Stock Options: at Proton, we all have the opportunity to be owners of the company. From day one, you have a real stake in what we're building. When Proton wins, you win.
• Technology: you'll get the right hardware and the right software you need to do your best work.
• Learning & Development: we invest in your growth because sharp people make us better. Proton is one of the fastest ways to accelerate your career because you'll be thrown into real challenges, with real ownership, from day one.
• Employee Benefits: your wellbeing isn't an afterthought. We offer strong health coverage, solid retirement options, generous leave, and wellness support so you can bring your best self to work every day
• In-Person Collaboration: Amazing things happen when passionate, smart, and purposeful people get together in the same room. With offices across Geneva, Zürich, Barcelona, London and more, you'll spend most of your time collaborating face-to-face with people who genuinely care about what they're building
• Food: Lunch and snacks are on us every day in our offices so you can focus on the work and not on what's for lunch.
• Transport: getting to the office shouldn't cost you. We cover public transport, bike allowances, or parking, whichever works for you.
• Flexible Working: you own your schedule. Set hours that work for you and your team — because outcomes matter more than when the clock says you started.

Our Commitment to Diversity and Inclusion

At Proton, we believe diversity drives innovation and strengthens our mission to provide privacy as a default for all. We are committed to fostering an inclusive environment where all individuals, regardless of race, ethnicity, gender, age, sexual orientation, physical ability, or socio-economic background, feel valued and empowered. We strive to create equal opportunities, promote open dialogue, and support continuous learning to ensure every voice is heard and respected.

If you need any extra support or reasonable adjustments during the hiring process, please let your talent partner know.

Candidate Privacy Notice

When you apply for a position, refer a candidate, or are considered for a role at Proton Technologies AG (Proton, we, us, or our), your information is stored in Greenhouse, in accordance with their Service Privacy Policy. This information is used to evaluate your suitability for the posted position. We also retain this information for consideration for future roles that you may apply for or that we believe may align with your background and skills.

If we no longer have a legitimate business need to process your information, we will either delete or anonymize it. Should you have any inquiries about how we use or manage your information, or if you wish to access, correct, or delete your data, please contact our privacy team at careers@proton.ch.

Proton does not accept unsolicited resumes from any sources other than directly from candidates. We will not pay a fee for any placement resulting from an unsolicited offer, even if the candidate is subsequently hired by Proton.

To learn more about our privacy policy, please visit our privacy policy page.

#LI-Onsite

We are looking for a Senior MLOps Engineer to add to our Data team in Barcelona.

Join the User Acquisition MLOps team that builds the core ML backbone of Appodeal. We design and run the systems that power real-time predictions at massive scale, where every millisecond matters. Our work directly drives thousands of bidding operations each second, supporting a high‑throughput, low‑latency inference platform used across the company.

You will help shape and evolve a modern ML platform built around Databricks, MLflow, Unity Catalog, GitHub Actions, and deep integrations with our Predictor service. This means solving real engineering challenges: scaling training pipelines, optimizing GPU workloads, ensuring safe and automated model promotions, and keeping online inference reliable under extreme load.

You will collaborate daily with Data Science, Data Engineering, Runtime, DevOps, and Product, and you will fully own the systems and projects you touch. This is a role for engineers who like autonomy, impact, and building things that matter.

Responsibilities:

• Design, operate, and improve the ML platform, including Databricks workflows for training, MLflow and Unity Catalog for model management, CI/CD pipelines using GitHub Actions and Databricks Asset Bundles, and integration with the runtime inference layer.
• Support data scientists in developing and maintaining end-to-end training pipelines, covering data processing, feature transformations, ML model training on GPUs, and distributed training setups to ensure efficient and scalable workflows.
• Ensure reliable and safe model inference by validating models before promotion, checking metadata compatibility, monitoring latency, and supporting model evaluation flows.
• Maintain strong ML observability, including online and offline monitoring, data and feature parity checks, and automated validation of model performance in production.
• Develop internal tools and APIs that enable DS teams and account managers to experiment, validate, and promote models efficiently while reducing operational friction.

Requirements:

• 3+ years of experience in MLOps, ML Platform Engineering, or Backend roles supporting production ML systems.
• Strong Python and software engineering skills, with experience building and maintaining APIs (FastAPI, Flask, or similar).
• Hands-on experience with DNNs using PyTorch or other modern deep learning frameworks, including GPU training and optimizing hardware utilization.
• Solid understanding of distributed computing and data processing using Apache Spark or similar frameworks.
• Experience with Databricks (Jobs, MLflow, Delta, UC) or an equivalent cloud-based ML platform.
• Strong understanding of the ML lifecycle: data ingestion, experimentation, model packaging, deployment, and monitoring.
• Familiarity with real-time model inference systems and ensuring compatibility with downstream services.
• Experience with data validation libraries (Pydantic or similar) used within ML and API workflows.
• Good understanding of Docker containers, Kubernetes, and basic networking concepts.
• Experience creating and maintaining CI/CD pipelines (GitHub Actions or similar).
• Experience with orchestration tools (Databricks Jobs, Dagster, Airflow or similar).
• Demonstrated ability to use modern AI tools (Claude, ChatGPT, Gemini) to improve development speed and quality.
• Proactive mindset with a strong sense of ownership, consistently pushing work forward and anticipating next steps without needing close direction.
• Strong English communication skills.

Nice to have:

• Exposure to very high-load, low-latency ML inference environments.
• Knowledge of distributed or large-scale ML training frameworks and multi-GPU setups.
• Familiarity with Databricks Asset Bundles.
• Understanding of ONNX or other portable model serialization formats.
• Ability to work with Rust programming language.
• Familiarity with transformer architectures, encoder-decoder models, or sequence modeling approaches.
• Exposure to data engineering concepts, such as building scalable data pipelines, understanding CDC patterns, or working with structured and unstructured datasets.
• Experience with MinIO or other S3-compatible storage systems.
• Understanding of networking protocols such as TCP, HTTP, and gRPC, including their limitations in low-latency scenarios.
• Confidence navigating the Atlassian ecosystem (Jira, Confluence, Compass).

This position supposes relocation to Barcelona and work from our office in the city center.

Why Join Us:

• Opportunity to work on cutting-edge projects with a global impact in the mobile app industry.
• A collaborative and inclusive work culture that values innovation and continuous learning.
• Competitive salary, flexible work arrangements, and a comprehensive benefits package.
• Professional development opportunities and career growth prospects within a fast-growing company.