Senior Foundation Engineer; Drive

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.

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Drive Foundation is the backbone of Proton Drive. We ensure that cross-client initiatives are executed consistently and efficiently. Whether it’s aligning multiple clients, maintaining documentation or the RFC process, or building robust SDKs, our team lays the groundwork that makes the entire Drive experience work seamlessly.

• Current Projects:
  • We’re currently focused on developing SDK that encapsulate the core functionality of Proton Drive. The SDK comes with two core implementations, one in C# for desktop and mobile clients and second in Type Script for web client, and higher-level modules in Rust. Our SDK primarily serve internal clients today, but our long-term vision includes integrating them across the Proton ecosystem—and even enabling third-party applications to interface with Drive.
• Tech Stack and Tools:
  • Languages we see daily is C#, Type Script and Rust. We also need to provide bindings for Swift and Kotlin. We use Grafana and Prometheus to instrument our SDK, Sentry to get details issues from the SDK usage, Git Lab CI for running tests including e2e tests written using Playwright, or Git Lab in general to work on the code base.
• Future Plans:
  • We are planning to revamp our cryptographic model to boost performance and efficiency across all clients. We will finish ongoing first generation of SDK to cover all core Drive features and new crypto model. Then we will do second generation in Rust with lessons learned and include full support of all features such as Photos, Public Sharing, and Docs.
• Foundation work touches every aspect of Drive
  . The SDK and infrastructure you build will be used by every Drive client
  —and getting it right is both critical and deeply rewarding.
• Drive is rapidly expanding. As it evolves into a true platform, we expect more teams to emerge—each owning different verticals built on top of Drive. This opens up immense opportunities to grow as an IC, tech lead or engineering manager.
• You’ll have the chance to shape not only the future of Drive, but also your own career path in a variety of domains and technologies.

As a Senior Drive Foundation Engineer, you will play a crucial role in designing, implementing, and maintaining the foundational components that power Proton Drive applications. You will work collaboratively with Drive teams, including backend, web, mobile, or desktop developers, to ensure seamless integration and optimal performance across various client applications.

• Architect and develop core libraries:Lead the design and development of core C#/Type Script/Rust libraries that serve as the backbone for Proton Drive's applications.
• Cross-platform compatibility:Ensure compatibility and optimal performance across various platforms.
• Code review and optimization:Conduct code reviews and provide constructive feedback to ensure code quality, maintainability, and performance optimization.
• Collaboration:Work closely with backend, frontend, mobile and desktop developers to integrate core libraries seamlessly into Proton Drive's applications.
• Testing:Develop and implement comprehensive testing strategies, including unit tests and integration tests, to ensure the reliability of core libraries.
• Documentation:Create and maintain…