Ilir Sela started Slice with the belief that local pizzerias deserve all of the advantages of major franchises without compromising their independence. Starting with his family’s pizzerias, we now empower over tens of thousands of restaurants with the technology, services, and collective power that owners need to better serve their digitally minded customers and build lasting businesses. We’re growing and adding more talent to help fulfil this valuable mission. That’s where you come in.

This position is open to applicants across all of the UK on a remote basis, with the physical office located in Belfast, Northern Ireland.

There are several openings within our Web team so we welcome applications from candidates seeking intermediate or senior level positions.

The Role

To continue scaling our Front-End teams we’re searching for an experienced software developer with a passion for Front-End development, particularly React and TypeScript. In this role, you will be instrumental in building world-class web products that empower small business owners.

You will take a lead in solving technical challenges and utilise your expertise to contribute to and guide important technical decisions across the team. You’ll be challenged with consistent hands-on contributions both autonomously and as a group. Your experience will be valuable in partnering with the technical leads and Development Manager, allowing them to focus on wider team and strategic initiatives, while you pilot technical responsibilities. Your ability to troubleshoot complex production issues and ensure high-quality test coverage will be crucial to our continuous delivery model.

The Team

You’ll join a dynamic team of Front-End Developers and the individuals you'll collaborate with are curious, motivated, and exceptionally proficient in their respective domains. They welcome challenging tasks and thrive on resolving them within an empowered and supportive setting. Our team brings together talented developers from across the US, Canada, UK, and Eastern Europe, each contributing unique perspectives and expertise to drive success. We work on products used by hundreds of thousands of customers and we ship changes live to production every day. There are no direct reports for this position but you’ll be comfortable coaching and mentoring others, sharing knowledge and setting examples to the wider team.

The Winning Recipe
We’re looking for creative, entrepreneurial engineers who are excited to build world-class products for small business counters. These are the core competencies this role calls for:

• 3+ years experience building applications with React
• 3+ years experience with TypeScript - you view TS as an invaluable tool and are an expert in its use
• Excellent investigative debugging skills and a proven ability to troubleshoot complicated and subtle problems in high availability production environments
• Proven experience delivering web experiences that meet standards for accessibility, performance, and SEO
• Proficient on driving high quality and appropriate test coverage
• You are a Front-End specialist but you understand aspects of the full tech stack and can contribute meaningfully to API design and overall system architecture

The Extras
Working at Slice comes with a comprehensive set of benefits, but here are some of the unexpected highlights:

• Access to healthcare plans
• Flexible working hours
• Generous time off policies
• Employee wellbeing allowance
• Market leading maternity and paternity schemes

The Hiring Process

Here’s what you can expect from our hiring process if your candidacy progresses smoothly. We move quickly and strive for a fast turnaround from the final interview to the offer.

• 30 minute introductory meeting with your Recruiter
• 60 minute Live Coding Interview
• 60 minute Technical Interview
• 30 minute hiring manager meeting
• Offer!

Pizza brings people together. Slice is no different. We’re an Equal Opportunity Employer and embrace a diversity of backgrounds, cultures, and perspectives. We do not discriminate on the basis of race, colour, gender, sexual orientation, gender identity or expression, religion, disability, national origin, protected veteran status, age, or any other status protected by applicable national, federal, state, or local law. We are also proud members of the Diversity Mark NI initiative as a Bronze Member.

Privacy Notice Statement of Acknowledgment

When you apply for a job on this site, the personal data contained in your application will be collected by Slice. Slice is keeping your data safe and secure. Once we have received your personal data, we put in place reasonable and appropriate measures and controls to prevent any accidental or unlawful destruction, loss, alteration, or unauthorised access. If selected, we will process your personal data for hiring /employment processes, as well as our legal obligations.

If you are not selected for the job position and you have given consent on the question below (by selecting "Give consent") we will store and process your personal data and submitted documents (CV) to consider eligibility for employment up to 365 days (one year). You have the right to withdraw your previously given consent for storing your personal data and CV in the Slice database considering eligibility for employment for a year. You have the right to withdraw your consent at any time.

For additional information and / or exercise of your rights to the protection of personal data, you can contact our Data Protection Officer, e-mail: privacy@slice.com

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 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!

• Our frontend is based on React
• Our backend API is based on PHP/Symfony
• 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

• Extensive experience with React, developing performant and reusable components
• Proficiency with TypeScript or any typed language
• Experience leading large and complex projects as a front engineer
• Bonus for B2B product experience and UX design experience

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)
• 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