Job Requirements

Strong experience in backend development, with a track record of designing, building and scaling systems that serve a large user base (100M+)
Demonstrated ability to improve the performance and cost-efficiency of systems already in production
Hands-on experience with monitoring and observability tooling (e.g. Grafana, OpenTelemetry, or equivalent), and a data-driven approach
Solid understanding of SQL (MySQL preferred) and data modeling
Experience leading a technical initiative end-to-end, from design through production

Bonus Points For

Experience with client-server sync or push-notification systems
Experience with Kubernetes or other containerization technologies
Experience with PHP/Symfony, Rust, or Python
Full-stack experience, comfortable working across the frontend as well as the backend

Architect and develop core systems: Design and build core, cross-product systems shared by Proton Mail and Calendar, with scale and cost-efficiency as first-class constraints.
Performance: Improve the performance of existing systems, using monitoring and metrics to identify where time and infrastructure spend are going and where to cut. Drive cost-reduction and efficiency initiatives across shared platform components, from proposal to production
Data-driven delivery: Bring a data-driven approach to technical decisions and delivery planning, shaping how the team measures and prioritizes its work
Collaboration: Work closely with a team of backend and clients engineers, with a strong emphasis on quality and performance in everything shipped
Testing: Develop and implement comprehensive testing strategies, including unit tests and integration tests, to ensure the reliability of core systems.

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.
Stock Options: At Proton, we all have the opportunity to be owners of the company. 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.
Employee Benefits: Strong health coverage, solid retirement options, generous leave, and wellness support.
In-Person Collaboration: Collaborate face-to-face with passionate and purposeful people.
Food: Lunch and snacks are on us every day in our offices.
Transport: We cover public transport, bike allowances, or parking.
Flexible Working: Set hours that work for you and your team because outcomes matter more than when the clock says you started.