Senior Back-End Engineer

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 organisations 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, coming 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'll 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 Role overview As our new Senior Back-End Engineer, you'll join the team responsible for Proton Pass and SimpleLogin. This role focuses on the back-end side of products, but you may also need to give a helping hand to our front-end teams. 

What you'll do Code in our shared back-end framework Work closely with a group of skilled back-end engineers and architects to build resilient, massively-scalable solutions for millions of people to rely on Collaborate with teams of client application developers to ensure that the back-end meets critical business and reliability requirements Document back-end capabilities and their proper use so that all Proton clients can implement correctly-functioning solutions Improve vital systems such as the systems responsible for cleaning up file revisions and returning quota to users What you'll bring Strong experience in back-end development Experience building scalable solutions Skills in OOP and SOLID Fluency in at least one strongly typed language Solid understanding of SQL (MySQL preferred) and data modelling Knowledge of unit and functional testing Solid understanding of security best practices Understanding of HTTP/REST, including both developing and consuming web-based APIs? Bonus points for Operational experience, such as SRE or on-call, demonstrating ability to diagnose and troubleshoot complex problems for critical systems  Experience with Docker or similar containerisation technologies Experience with CI/CD (Gitlab, Jenkins, etc.) Experience with back-end web frameworks (Symfony, Spring, .NET) Experience with modern PHP, Rust and Python High-level understanding of cryptography concepts such as key exchange and the difference between symmetric and asymmetric encryption Experience with DDD (Domain-Driven Design) and other enterprise patterns Experience with metrics graphing/analysis toolkits such as Grafana and OpenTelemetry Solid understanding of Redis or other caching technologies Experience with OpenAPI specs or other API documentation frameworks Even if you don't meet all the requirements listed above but feel you could still be a great fit, please do apply.

What we offer 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 Learning & Development: we are committed to your professional growth – Proton offers various learning opportunities, including training programs, conferences/events and continual learning Employee Benefits: comprehensive health insurance plans, competitive retirement savings options, generous vacation/leave policies and wellness programs Stock Options: at Proton, we are all owners of the company and you get stock options when you join us In-Person Collaboration: 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 enjoy working from home for up to 30% of the time, while enjoying great company culture during our three core days in the office (depending on the role, fully remote positions may also be available) Food: lunch and snacks are provided by Proton every day at our offices Transport: we'll always support our employees with transport costs through subsidising public transport, bike allowances or parking spaces based on your office location Flexible Working: you can define your own working hours as long as it works with team meetings Work that Matters: Proton is a community-first organisation, 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 its 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 anonymise 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 ******** .

Proton does not accept unsolicited CVs 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.