Requirements:

• 5+ years building and operating backend systems in production, including code you stayed responsible for long after launch, with a focus on modern PHP
• Working knowledge of Rust, or clear evidence you can get there quickly — we care that you understand ownership and lifetimes
• Genuine taste in API design. You have opinions about naming, defaults, error handling, and what belongs in a library versus a service
• A feel for architecture at codebase scale — you have worked somewhere large enough that module boundaries and dependency direction mattered, and you have views on what keeps a monorepo healthy
• Experience evolving shared code that other teams depend on, and doing it without breaking them
• A security mindset. You think about how the abstraction you just wrote will be misused
• The influence to get an internal library adopted rather than worked around, and the patience to carry a design through disagreement between two teams who both think they're right

Nice to Haves:

• Domain-Driven Design, or similar experience modelling complex domains where the boundaries matter
• Background in developer tooling, platform, or DX teams
• Contributions to open source, especially libraries with real users
• Experience migrating a codebase incrementally between architectures or languages
• Experience with applied cryptography, key management, or end-to-end encrypted systems
• Experience with building CI/CD

What You'll Be Doing:

• Design and build shared libraries, framework layers, and internal services used across every Proton product
• Turn recurring patterns into good abstractions
• Write documentation and examples people actually use, and treat adoption as part of shipping
• Improve the day-to-day: build times, local dev setup, test ergonomics, debuggability, developer experience
• Work in the open with product teams — RFCs, design reviews, and the occasional pull request into someone else's repo to show what you mean
• Work closely with other developers to help integrate libraries seamlessly into applications

Perks and Benefits:

• 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.
• Work with smart and dedicated people: Our team is diverse, collaborative, and tight-knit with people coming from all walks of life.
• 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: your wellbeing isn't an afterthought. We offer strong health coverage, solid retirement options, generous leave, and wellness support.
• Stock Options: at Proton, we all have the opportunity to be owners of the company.
• In-Person Collaboration: Amazing things happen when passionate, smart, and purposeful people get together in the same room.
• Food: Lunch and snacks are on us every day in our offices.
• Transport: getting to the office shouldn't cost you. We cover public transport, bike allowances, or parking.
• Flexible Working: you own your schedule. Set hours that work for you and your team.