Senior Backend Engineer Foundation

Senior Backend Engineer Foundation Overview

Join a privacy-focused company that builds products used by millions of people around the world. The organization was started by scientists from CERN in 2014 and is built around the idea that privacy is a basic human right. Its product suite includes encrypted email, VPN, cloud storage, password management, and calendar tools, all designed to help people protect their data, preserve freedom, and resist censorship. The company describes itself as profitable, independent, and selective in hiring, with a large international team spread across many countries.

This role sits on the Foundation team, which is responsible for the shared backend layer that other product teams build on top of. The team creates the common libraries, internal services, and framework pieces that should exist once and be reused everywhere they are needed. The work is central to keeping the codebase maintainable, consistent, and scalable across many teams working in the same monorepo.

What you will work on

• Designing and building shared backend libraries, framework components, and internal services that are used across Proton’s products.
• Turning repeated implementation patterns into clean, reusable abstractions.
• Owning platform or library initiatives from the first design discussion through implementation, documentation, versioning, and migration planning for existing users of older versions.
• Helping shape the architecture of a large monorepo by defining module boundaries, dependency flow, and ownership responsibilities.
• Writing RFCs, introducing rules or guardrails, and resolving structural issues such as dependency cycles.
• Working closely with product teams that consume the shared platform so the tools you build fit real needs and integrate smoothly.
• Participating in design reviews, open technical discussions, and occasional pull requests in other teams’ repositories to clarify or demonstrate an approach.
• Improving engineering productivity by making builds faster, local development easier, tests more usable, and debugging more effective.
• Helping other engineers adopt shared libraries successfully and use them in applications without friction.
• Using PHP for API-related backend work and Rust for performance-sensitive components or microservices where memory safety and efficiency are important.

What the team is looking for

• At least five years of production backend experience, including long-term ownership of systems after launch, with strong experience in modern PHP.
• Practical familiarity with Rust, or a clear ability to learn it quickly, especially with an understanding of ownership and lifetimes.
• Strong instincts for API design, including naming, defaults, error handling, and deciding whether functionality belongs in a library or a service.
• Experience working at codebase scale, where architecture, module boundaries, and dependency direction materially affect maintainability.
• Experience changing shared code that other teams rely on, while keeping those teams productive and avoiding breakage.
• A security-conscious approach to design, including thinking ahead about how abstractions could be misused.
• The ability to persuade others to adopt an internal library or platform component rather than bypassing it.
• Patience and communication skills to work through disagreements between teams that each believe their approach is best.
• Comfort working in a large monorepo or similarly complex environment where structural decisions matter.

Helpful additional experience

• Domain-Driven Design or similar methods for modelling complex domains with clear boundaries.
• Experience on developer tooling, platform engineering, or developer experience teams.
• Open-source contributions, especially to libraries that have real users.
• Incremental migration work between architectures or programming languages.
• Applied cryptography, key management, or end-to-end encrypted systems.
• Building CI/CD systems.

The employer also encourages people to apply even if they do not match every requirement, as long as they believe they could be a strong fit for the role.

What Proton offers

• Work with clear purpose and measurable impact, since the company serves millions of people who depend on its privacy tools.
• A mission-driven environment that is independent of advertisers and outside investors with conflicting agendas.
• Colleagues who are described as smart, dedicated, collaborative, and highly accomplished, with backgrounds from leading universities and organizations.
• The equipment and software you need to do strong work.
• Support for learning and professional development, with the expectation that the role will stretch you through real responsibility from day one.
• Health coverage, retirement support, generous leave, and wellness support.
• Stock options so employees can share in the company’s success.
• Regular in-person collaboration in offices including Geneva, Zürich, Barcelona, and London.
• Lunch and snacks provided in the office each day.
• Support for commuting costs, including public transport, bike allowances, or parking.
• Flexible working hours, with schedules set around outcomes rather than a fixed clock-in time.

Work environment and culture

The company emphasizes a light hierarchy, fast execution, and impact over appearances. It also highlights a diverse and inclusive culture and says it is committed to creating equal opportunity and open dialogue for people of all backgrounds. If a candidate needs support or reasonable adjustments during hiring, they are encouraged to tell their talent partner.

The application form asks candidates to provide their contact details, resume, cover letter, links to LinkedIn, GitHub, or a portfolio, salary expectations, start date, and whether they are open to working three days per week in the London or Paris office. It also asks whether the candidate has the right to work in the relevant location and, if so, what kind of permission they hold.

Applicants are directed to submit their application through the Greenhouse form on the page.

Degree Requirement: Not Specified

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