Senior Windows Engineer (Drive)

Proton, the privacy‑focused company founded by CERN scientists in 2014, builds free, open‑source services such as Proton Mail, Proton VPN, Proton Calendar, Proton Drive and Proton Pass. As a Senior Windows Engineer (Drive) you will help shape the Windows client for these tools, ensuring that users can store and sync data securely while keeping privacy as the default setting. In this role you will design, implement and evolve the Windows application, handling everything from internal logic and cryptographic operations to state synchronization between local and remote stores. You will take part in the full lifecycle, configuring GitLab pipelines, managing deployments, setting up monitoring and alerts, and responding to operational incidents. Collaboration with backend engineers is expected to align the client with server‑side changes and new features, while you also drive testing and automation to boost delivery speed. The position requires strong .NET development experience and a proven track record of building and maintaining desktop Windows applications. You must be comfortable with concurrent multi‑threaded programming, have practical knowledge of file systems and Git, and hold a bachelor’s or master’s degree in a relevant discipline. Experience in owning large software components and working with gradual rollouts, metrics, monitoring and alerting frameworks is also essential. Proton offers a hybrid “Office First” model with locations in Geneva, Zurich, Prague, Barcelona, Paris, London, Vilnius, Skopje and Taipei, plus up to 30 % remote work. Employees receive the necessary hardware and software, daily lunch and snacks, and transport subsidies. Stock options are part of the compensation package, and the company’s flat, start‑up‑like culture emphasizes empowerment, flexibility and rapid innovation.