Windows Software Engineer (VPN)

Location: Hybrid in Barcelona or Vilnius, requiring 3 days in office weekly.

Company

Proton was founded in 2014 by scientists from CERN, built the world’s largest encrypted email service and expanded into VPN, Drive, Pass, and Calendar, with a 500+ team across 50+ countries focused on privacy as a fundamental human right.

What you will do

• Design, build, maintain, and evolve Proton’s Windows applications.
• Manage the entire application lifecycle, from feature design to deployment and monitoring.
• Collaborate with product managers and engineers to deliver privacy-preserving products.
• Develop primarily in .NET and WinUI, integrating Rust-based core libraries.
• Define, maintain, and improve the testing stack, including unit, integration, and automated GUI tests.

Requirements

• Strong experience in C# and .NET development.
• Strong experience building Windows desktop applications using WinUI, WPF, or similar.
• Solid understanding of MVVM architecture, dependency injection, asynchronous programming, and event-based messaging patterns.
• Proven ability to write maintainable, well-tested, and scalable codebases.
• Working knowledge of networking fundamentals (TCP/IP, DNS, routing concepts) and an interest in VPN technologies.
• Experience with code debugging, profiling, and performance optimization on Windows.
• Familiarity with Git-based workflows, CI/CD (GitLab), and observability tooling (telemetry, metrics, monitoring and alerting).
• Hybrid work in Barcelona or Vilnius, requiring 3 days in office weekly.

Nice to have

• Rust experience is a significant plus.

Culture & Benefits

• Office-first hybrid model, requiring 3 days in the office and allowing up to 30% work from home.
• Provided devices and software to support your role.
• Daily lunch and snacks provided at the offices.
• Transport costs subsidization through public transport, bike allowances, or parking.
• Company stock options for all employees.
• Flexible working hours.
• Various learning and development opportunities, including training programs, conferences, and continual learning.
• Comprehensive health insurance, competitive retirement savings, generous vacation and leave policies, and wellness programs.
• Opportunity for meaningful work in a community-first organization focused on privacy.