Why Valtech? We’re the experience innovation company - a trusted partner to the world’s most recognized brands. To our people we offer growth opportunities, a values-driven culture, international careers and the chance to shape the future of experience. 

The opportunity

At Valtech, you’ll find an environment designed for continuous learning, meaningful impact, and professional growth. Whether you're pioneering new digital solutions, challenging conventional thinking or building the next generation of customer experiences, your work will help transform industries. 

We are proud of: 

• The work we do and the innovation we drive 
• Our values of share, care and dare 
• A workplace culture that fosters creativity, diversity and autonomy 
• Our borderless, global framework, which enables seamless collaboration 

The role  

Valtech is looking for a Flutter Lead Developer to shape our cross-platform mobile and web application landscape. In this role, you will own the technical strategy, architecture, and delivery of scalable, high-performing Flutter applications that power digital experiences across our business. Working at the intersection of design, development, and product, you’ll lead a cross-functional team of developers and testers, define best practices, and transform ideas into elegant, responsive, and maintainable apps. You will play a key role in driving technical excellence and Flutter adoption, while mentoring others and contributing to a culture of innovation and quality.

Role responsibilities

• Lead Flutter mobile app development across Android / iOS.
• Focus on best engineering practices for quality, clean code, testing & observability.
• ⁠Architect scalable, maintainable, and performant mobile solutions.
• Mentor and guide Flutter developers; conduct code reviews.
• Collaborate with product, design, and backend teams.
• Ensure code quality, testing, and CI/CD integration.
• Stay updated with Flutter/Dart trends and best practices.
• Manage technical risks and project timelines.

Must have qualifications

To be considered for this role, you must meet the following essential qualifications: 

• 7+ years of total development experience, with at least 3+ years in Flutter development. 
• Strong knowledge of data structures, modern design patterns, and best practices in object-oriented software engineering. 
• The ability to write clean and neat code that is easy to maintain. 
• The ability to cover all (or almost all) your work with tests. 
• Understanding the principles of user interface design. 
• Expert knowledge of the Dart language.
• Experience developing native applications (Android/iOS) will be a plus. 
• Knowledge of development and configuration tools (Git, Jira, Jenkins, etc.). 
• Experience with RESTful APIs to connect to back-end services. 
• Knowledge of modern architectural patterns in mobile development (BLoC, MVVM) and the principles of functional programming. 
• Understanding the principles of DRY and SOLID principles. 
• Experience in creating multi-module projects.
• Advanced level of English, both written and verbal.

If you do not meet all the listed qualifications or have gaps in your experience, we still encourage you to apply. At Valtech, we recognize that talent comes in many forms, and we value diverse perspectives and a willingness to learn. 

Commitment to reaching all kinds of people 

We design experiences that work for all kinds of people - and that starts with our own teams. At Valtech, we’re intentional about building an inclusive culture where everyone feels supported to grow, thrive and achieve their goals. No matter your background, you belong here. Explore our Diversity & Inclusion site to see how we’re creating a more equitable Valtech for all. 

The benefits  

• Private health insurance
  We hope you will never need it, but nevertheless, we offer private health insurance to all our employees.

• Education program
  We never stop learning, that’s why we offer our employees an educational program with training and certification.

• Wellbeing program
  We all deserve to live a healthy and well-balanced life. It's not an option, it's a necessity!

• Free beverages
  Enjoy free coffee, drinks, and snacks at work, or join one of our famous company dinners.

• Events
  We enjoy spending time together, not only at work. Ski trips, carting, laser-tag, wine tasting, picnics, cooking classes… you name it – we’ve done it! There are plenty of cool events to join and to get to know your colleagues.

• Competitive conditions
  Besides a competitive salary and 24 days of vacation, you will join annual company events with the whole team.

• Challenging projects
  Ready for a challenge? We guarantee you'll find challenging projects at Valtech!
  
  
• Cool colleagues
  What's the most important thing in a job? Cool colleagues with whom you spent most of the time during the week. We have a lot of them!
  
  
• Honest feedback
  Honesty, openness and respect are among our core values. We encourage an open feedback culture in order to build trust and grow together.

Your application process

Once you apply, our Talent Acquisition team will review your application. Your CV should cover key information on relevant experiences and expertise. We do not require information such as age, gender, marital status, or a headshot in your application. We review all candidates based on skills, experience, and potential.

⚠️ Beware of recruitment fraud!

We are committed to inclusion and accessibility. If you need reasonable accommodations during the interview process, please either indicate it in your application or let your Talent Partner know. 

About Valtech

Valtech is the experience innovation company that exists to unlock a better way to experience the world. By blending crafts, categories, and cultures, we help brands unlock new value in an increasingly digital world. 

At the intersection of data, AI, creativity, and technology, we drive transformation for leading organizations, including L’Oréal, Mars, Audi, P&G, Volkswagen Dolby, and more. 

At Valtech, we don’t just talk about transformation. We make it happen. Our people are the heart of our success, and we foster a workplace where everyone has the support to thrive, grow and innovate. 

Are you ready to create what’s next? Join us.

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

At Proton, we believe that privacy is a fundamental human right and the cornerstone of democracy. Since our inception in 2014, founded by a team of scientists from CERN, we have dedicated ourselves to providing free and open-source technology to millions worldwide, ensuring access to privacy, security, and freedom online.

Our journey began with Proton Mail, the largest secure email service globally, and has since expanded to include Proton VPN, Proton Calendar, Proton Drive, and Proton Pass. These tools empower individuals and organizations to take control of their personal data, break away from Big Tech’s invasive practices, and defeat censorship. Our work impacts hundreds of millions of lives, from activists on the front lines defending freedom to leaders in governments protecting sensitive information. In some cases, Proton’s services have even been instrumental in saving lives by enabling secure and private communications in high-risk situations.

Proton is a profitable company that does not rely upon VC funding, supporting over 100 million user accounts with a growing team of over 500 people from over 50 different countries, from the world's top companies and universities. We value intelligence, learning potential, and ambition in our hiring process. Adaptability is key as we navigate uncharted territories and redefine how business is conducted online.

Hiring at Proton is highly selective, with less than 1% of candidates hired. We believe smaller teams of exceptional talent will always prevail over larger teams with lower talent density. You will have the opportunity to work with many of the world's top minds in their fields, ranging from former international math and science olympiad winners to chess champions.

We have a global mindset and big ambitions but remain a start-up at heart. We value empowerment and flexibility and keep our structure flat to keep moving fast and avoid unnecessary politics. Tired of blending into the crowd? Join us and do work you can truly be proud of. Check our open-source projects here!

Purpose of the role

MSA is a highly multi-disciplinary group started in 2019 to tackle difficult mail delivery, spam, abuse, and account security problems that impact the Proton ecosystem. We built sophisticated systems from scratch that combine human intelligence and machine learning to make tens of millions of realtime or asynchronous decisions each day. Our custom systems have reduced spam filter misclassifications by over 60%, blocked millions of abusive bulk signups, protected hundreds of thousands of users from account compromise by attackers, and mitigated hundreds of DDoS attacks. In the last few years, we have also been building complicated new products, including launching Wallet, Lumo AI, and Meet. We are the main group at Proton working on AI. In order to move fast with limited resources, we are organized into autonomous teams responsible for the whole system, with expertise across infrastructure, data storage, backend, web and mobile apps, machine learning, security and operational excellence. We are looking for humble, mission-driven, systems-thinking people who want to make a big impact in a startup environment.

What you will do

MSA builds and operates many services responsible for different domains. You will:

• work with other engineers and analysts to design, build, and operate these systems
• work on special user-facing features involving frontend and backend software development
• You will have the opportunity to play Product or Project Managers roles and lead the whole planning and development process
• be responsible for the operational excellence of the systems/features and their interaction with other systems
• You may work on MSA's custom systems written in Python or on the main Proton API written in PHP or on Proton Web apps written in React or even on native iOS and Android mobile apps

Job requirements

• Deep experience with backend development (Python, PHP, or Go)
• Experience with frontend design and development (JavaScript, React, Typescript, or jQuery)
• Experience building complex production systems
• Experience with data processing and storage (MySQL, MongoDB, Redis, Kafka, Elastic, Ceph, ClickHouse)
• Able to work autonomously and lead the whole development process, from design to QA
• Experience with AI tools and AI agents
• Excellent English communications, both written and spoken

Bonus points for: 

• experience with machine learning and real-time prediction systems
• experience with iOS or Android app development
• experience with managing Linux servers, including infrastructure as code (Puppet, Ansible) and containerization

What We Offer

• Office First: Collaboration is easier and more effective in person, which is why we have offices in Geneva, Zurich, Prague, Barcelona, Paris, London, Vilnius, Skopje, and Taipei. You can also enjoy working from home up to 30% of the time, while enjoying great company during our three core days in the office. 
• Technology: We provide all the devices and software you need to excel in your role, ensuring you have the best tools at your disposal to achieve your goals.
• Food: Lunch and snacks are provided by Proton every day at our offices.
• Transport: We will always support our employees with transport costs through subsidizing public transport, bike allowances, or parking spaces based on your office location.
• Stock Options: At Proton, we are all owners of the company and you get stock options when you join us.
• Flexible Working: You can define your own working hours as long as it works with team meetings.
• Learning and Development: We are committed to your professional growth. Proton offers various learning opportunities, including training programs, conferences and events, and continual learning.
• Employee Benefits: Comprehensive health insurance plans, competitive retirement savings options, generous vacation and leave policies, and wellness programs.
• Work that Matters: Proton is a community-first organization, started with the support of a crowdfunding campaign and built with community input. To this day, Proton’s only source of revenue is user subscriptions. Over 100 million people trust and support Proton, and we put our users and community first in everything we do. Read more about our impact here.

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

At Proton, we believe that privacy is a fundamental human right and the cornerstone of democracy. Since our inception in 2014, founded by a team of scientists from CERN, we have dedicated ourselves to providing free and open-source technology to millions worldwide, ensuring access to privacy, security, and freedom online.

Our journey began with Proton Mail, the largest secure email service globally, and has since expanded to include Proton VPN, Proton Calendar, Proton Drive, and Proton Pass. These tools empower individuals and organizations to take control of their personal data, break away from Big Tech’s invasive practices, and defeat censorship. Our work impacts hundreds of millions of lives, from activists on the front lines defending freedom to leaders in governments protecting sensitive information. In some cases, Proton’s services have even been instrumental in saving lives by enabling secure and private communications in high-risk situations.

Proton is a profitable company that does not rely upon VC funding, supporting over 100 million user accounts with a growing team of over 500 people from over 50 different countries, from the world's top companies and universities. We value intelligence, learning potential, and ambition in our hiring process. Adaptability is key as we navigate uncharted territories and redefine how business is conducted online.

Hiring at Proton is highly selective, with less than 1% of candidates hired. We believe smaller teams of exceptional talent will always prevail over larger teams with lower talent density. You will have the opportunity to work with many of the world's top minds in their fields, ranging from former international math and science olympiad winners to chess champions.

We have a global mindset and big ambitions but remain a start-up at heart. We value empowerment and flexibility and keep our structure flat to keep moving fast and avoid unnecessary politics. Tired of blending into the crowd? Join us and do work you can truly be proud of. Check our open-source projects here!

The team:

You strive for perfection and are obsessed with details? You are the one that catches the needle in the haystack in no time? You have a strong background in Quality Assurance and good technical skills? You like to work in a young and dynamic environment? Our QA team is looking for you.
This team is part of our VPN department. The team members are spread in different office locations across Europe. They are responsible for raising the quality standards of our native clients on all platforms as well as maintaining, improving and executing test plans. They are working in strict contact with our automation engineers to get repetitive tasks implemented in our automated test suites while focusing on the improvements of the testing process. Also, they work hand-in-hand with the development and product teams and will provide quality feedback on every stage of the software development lifecycle.

Tech Stack and Tools:

Apple, XCode, XCTest

What you will do:

As our iOS Test Automation Engineer, you’ll be the guardian of app quality. You will:

• Design, build, and maintain automated test frameworks and test suites for iOS.

• Collaborate closely with product managers, designers, and developers to ensure features are testable and reliable.

• Integrate test automation into CI/CD pipelines to deliver fast, smooth, and fearless releases.

• Debug, analyze, and triage test failures — helping the team get to the root cause quickly.

• Continuously explore new tools, frameworks, and practices to improve test coverage, speed, and scalability.

What we are looking for:

• 5+ years of test automation experience, with a focus on iOS apps.

• Strong coding skills in Swift (bonus if you know Objective-C too).

• Experience with iOS testing frameworks XCTest/XCUITest.

• Familiarity with CI/CD pipelines (Gitlab, Harbor, Docker).

• A quality-first mindset and a passion for clean, maintainable code.

• Team-player energy — you love collaborating to build products users love.

Bonus points for:

• Experience with device clouds (Firebase Test Lab, BrowserStack, Saucelabs).

• Knowledge of API testing (REST, GraphQL) to validate end-to-end scenarios.

• Experience with performance, load, or accessibility testing for mobile apps.

• Contributions to open-source testing tools or your own side projects.

What We Offer:

• Office First: Collaboration is easier and more effective in person, which is why we have offices in Geneva, Zurich, Prague, Barcelona, Paris, London, Vilnius, Skopje, and Taipei. You can also enjoy working from home up to 30% of the time, while enjoying great company during our three core days in the office. 
• Technology: We provide all the devices and software you need to excel in your role, ensuring you have the best tools at your disposal to achieve your goals.
• Food: Lunch and snacks are provided by Proton every day at our offices.
• Transport: We will always support our employees with transport costs through subsidizing public transport, bike allowances, or parking spaces based on your office location.
• Stock Options: At Proton, we are all owners of the company and you get stock options when you join us.
• Flexible Working: You can define your own working hours as long as it works with team meetings.
• Learning and Development: We are committed to your professional growth. Proton offers various learning opportunities, including training programs, conferences and events, and continual learning.
• Employee Benefits: Comprehensive health insurance plans, competitive retirement savings options, generous vacation and leave policies, and wellness programs.
• Work that Matters: Proton is a community-first organization, started with the support of a crowdfunding campaign and built with community input. To this day, Proton’s only source of revenue is user subscriptions. Over 100 million people trust and support Proton, and we put our users and community first in everything we do. Read more about our impact here.

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) - 55.000 - 71.000 EUR gross annual 

#LI-Onsite