Senior Backend Engineer (Foundation) at Proton

Department: CC - Foundation

Language

Setup: On-site
Location: Paris, Île-de-France · London, England
Type: Full-time
Level: senior
Posted: Aug 18, 2026

Description

Proton is hiring a Backend Engineer for its Foundation team to build shared libraries, framework layers, internal services, APIs, and microservices used across its products. The role focuses on modern PHP and Rust, architecture at codebase scale, monorepo boundaries, documentation, developer experience, RFCs, design reviews, and migrating shared code without breaking dependent teams. Candidates need at least five years of production backend experience, strong API and architecture judgment, and a security mindset; the role is onsite in one of Proton’s offices.

Required Skills

PHP
Rust
API design
Architecture
Monorepo
Microservices
Cryptography
CI/CD

Additional Information

Required Previous Experiences: 5+ years building and operating production backend systems, including long-term ownership of code, with a focus on modern PHP
Experience evolving shared code used by other teams without breaking them
Experience working at codebase scale with module boundaries, dependency direction, and monorepo architecture
Preferred Qualifications: Domain-Driven Design or similar experience modelling complex domains
Background in developer tooling, platform, or developer experience teams
Open-source contributions, especially libraries with real users
Experience incrementally migrating a codebase between architectures or languages
Applied cryptography, key management, or end-to-end encrypted systems
CI/CD experience
Translation Company Name: Proton