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. We are profitable and independent with no VC control. If you want to do meaningful work with exceptionally high-caliber people, this is it. Check our open-source projects here
As an engineer on our small Windows VPN team, you will be responsible for designing, building, maintaining, and evolving Proton’s applications on Windows. You will be involved in the entire application lifecycle, from feature design and implementation to CI/CD configuration, deployment, monitoring, and operational incident response. NET and WinUI (C#/XAML), and we are building and integrating cross‑platform logical core libraries written in Rust.




Software quality is central to this role. You will help define, maintain, and improve our testing stack, which includes unit tests, integration tests, and automated GUI tests (using FlaUI).
Strong experience in C# and .NET development.
Strong experience building and maintaining Windows desktop applications using frameworks such as WinUI, WPF, or similar.
Proven ability to write maintainable, well‑tested, and scalable codebases.
Demonstrated experience driving change within an organization and leading complex technical projects
A strong understanding of software architecture and engineering best practices.
An appreciation for user experience and design quality.
Rust experience is not required but is a significant plus.
Working knowledge of networking fundamentals (TCP/IP, DNS, routing concepts) and an interest in VPN technologies and protocols.
Experience with code debugging, profiling, and performance optimization on Wi

📌 Software Engineer, Windows (Cataluña)
🏢 Proton
📍 Cataluña