Senior Backend Engineer (Inbox)

<p><strong>Join Proton and build a better internet where privacy is the default</strong></p> <p>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.</p> <p>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.</p> <p>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.</p> <p>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.</p> <p>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.<span> </span><span>Check our<span> </span></span><span>open-source<span> </span></span><span>projects<span> </span></span><a href="https://proton.me/community/open-source"><span>here</span></a><span>!</span></p> <p><strong>Role overview</strong></p> <p>Become part of the team that drives the development of Proton Mail and Proton Calendar. While your focus will be on the back-end architecture of these products, close collaboration with front-end teams is essential. You'll play a key role in designing and delivering robust, scalable systems that serve millions of users globally. </p> <p><strong>What you'll do</strong></p> <ul> <li>Take ownership of complex, cross-functional projects driving them from planning to execution, while ensuring team priorities are <br/>successfully met</li> <li>Work closely with back-end and front-end (Web, Mobile, Desktop) engineers to build solutions while considering client limitations such as <br/>performance, bandwidth and device-specific constraints</li> <li>Proactively identify and initiate new work streams and projects to drive forward team objectives</li> <li>Demonstrate a product-oriented mindset, focusing on product engineering and design that meets the needs of the end-user</li> <li>Collaborate with teams of client application developers to ensure that the back-end meets critical business and reliability requirements</li> </ul> <p><strong>What you'll bring</strong></p> <ul> <li>Strong experience in back-end development with a proven track record of working closely with client-side teams (Web, Mobile)</li> <li>Experience in leading cross-functional projects, coordinating across multiple teams to deliver complex solutions</li> <li>Strong product engineering mindset, with a focus on designing back-end systems that drive excellent user experience</li> <li>Experience building scalable solutions, especially for systems that serve a wide variety of clients</li> <li>Fluency in OOP and SOLID</li> <li>Solid understanding of SQL (MySQL preferred) and data modelling</li> <li>Good knowledge of unit and functional testing</li> <li>Strong understanding of security best practices</li> <li>Understanding of HTTP/REST, including both developing and consuming web-based APIs </li> </ul> <p><strong>Bonus points for</strong></p> <ul> <li>Operational experience, such as SRE or on-call, demonstrating ability to diagnose and troubleshoot complex problems for critical systems </li> <li>Experience with Docker or similar containerisation technologies</li> <li>Experience with CI/CD (Gitlab, Jenkins, etc.)</li> <li>Experience with back-end web frameworks (Symfony, Spring, .NET)</li> <li>Experience with modern PHP, Rust and Python</li> <li>High-level understanding of cryptography concepts such as key exchange and the difference between symmetric and asymmetric encryption</li> <li>Experience with DDD