Senior Android Software Engineer - Paris

About Proton Join Proton and build a better internet where privacy is the default Proton was founded in 2014 by scientists from CERN on a simple truth: privacy is a fundamental human right . Since then, we’ve built the world’s largest encrypted email service (Proton Mail) and expanded into Proton VPN, Proton Drive, Proton Pass, and Proton Calendar—tools used by millions globally to protect their freedom, fight censorship, and keep their data safe. In some situations, Proton has literally helped save lives! We are profitable, independent (no VC control), and selectively hire from the top ~1% of applicants. Our 500+ team members across 50+ countries come from leading organizations and elite academic backgrounds. We move fast, keep hierarchy light, and prioritize impact over optics. If you want to do meaningful work with exceptionally high-caliber people, this is it. Join us and do work you can truly be proud of. Check our open-source projects here ! The Role Based in our Paris office, you’ll join one of several high-impact product teams focused on Inbox (Proton Mail and Calendar), Proton Account, Lumo, and Meet, helping build the foundational experiences that power Proton’s ecosystem and the next generation of privacy-first products. From authentication, identity, and account security to privacy-preserving AI experiences and secure online collaboration tools, you’ll work on technically ambitious products with real-world impact. As a senior engineer, you’ll collaborate closely with product, design, and engineers across Proton to build and ship high-quality Android experiences using Kotlin, Jetpack Compose, and an increasingly shared Rust core, helping define what “great” looks like for privacy-focused consumer products at scale. What we are looking for You have extensive experience building and shipping high-quality Android applications using Kotlin You have strong experience with Jetpack Compose and modern Android development practices You care deeply about product quality, usability, and delivering exceptional user experiences You have experience taking end-to-end ownership of features, from scoping and technical design through to delivery and iteration You have strong experience building maintainable, scalable, and testable mobile architectures You are comfortable working across large codebases and collaborating across multiple teams You have experience mentoring engineers and raising the technical bar within a team You have a strong understanding of performance, concurrency, multithreading, and mobile memory management You understand mobile scalability considerations, including caching, network usage, responsiveness, and offline behaviour You are comfortable navigating ambiguity and contributing to product and technical discussions Experience with privacy, security, encryption, sync systems, or offline-first architectures is a strong plus Rust experience is a plus, but not required, as we continue moving…