.NET/C# Developer

Job description

Our company:

Our mission is to defend human rights and democracy through building software that is essential for digital freedom and privacy protection for all Internet users.

ProtonMail was founded in 2014 by a group of scientists who met at the European Organization for Nuclear Research (CERN). And since its inception, the company has grown at a fast pace and today has over 26 million users. Our principal product, ProtonMail, is the world’s largest secure email service. Our second product, ProtonVPN, is one of the world’s most popular VPN services. Our vision is to build an Internet platform for the protection of digital rights, and we are also developing additional products such as ProtonCalendar, ProtonDrive, and much more.

Proton users include leaders of the Hong Kong protest movement, New York Times journalists, some of the world’s largest corporations, and millions of ordinary citizens from over 180 countries. Our team is diverse and dynamic, representing over 30 different nationalities, with offices in Geneva, Zurich, Prague, Vilnius, Skopje, San Francisco, and Taipei.


About the position:

We are looking for an enthusiastic .net & C# Developer to become part of our ProtonVPN team.

ProtonVPN clients support all major platforms, including Windows. We want to build a secure product that is competitive on usability, functionality, and stability, to offer our users the best VPN experience.

You will improve and extend the ProtonVPN client by building user interfaces, optimizing network protocols, and creating Windows kernel drivers. You will also work in close collaboration with the entire ProtonVPN development team on any outstanding projects. The ideal candidate thrives in a challenging environment that requires a variety of skills.


What You will do:

You will be an active part of the ProtonVPN Windows team through tasks including, but not limited to:

  • Collaborating in the analysis of complex challenges related to various aspects of a Windows system, related but not limited to its networking stack
  • Taking part in the development of innovative solutions to improve the interface, usability, connectivity, stability, performance, and resilience of ProtonVPN and extend its functionality
  • Taking part in extending existing open source projects or in creating new ones


Job requirements

  • Expert-level knowledge of Windows
  • Good knowledge of the C# ecosystem
  • A documented track record of contributions to multiple Windows projects and applications
  • Strong software engineering skills
  • Knowledge of the networking stack (especially on the Windows environment)
  • Basic understanding of the principles of quality assurance


Bonus points for:


  • Windows Kernel driver development
  • VPN protocols such as OpenVPN, IKEv2 or WireGuard
  • Windows system administration
  • Code debugging and profiling
  • HTTPS certificates and public key infrastructure
  • Agile methodologies and frameworks
  • Open source software development


Why you should join Proton

  • We work on interesting, challenging problems every day. There is never a dull moment.
  • Our startup culture means everyone’s opinion matters. You can have a significant impact.
  • Our rapid growth means there are many opportunities for advancement.
  • The chance to do something meaningful. Proton products protect dissidents, journalists, and activists. Our work saves lives.
  • Be part of something bigger. Millions of people and businesses around the world have embraced our idea of an Internet where privacy and security are the default. Join the privacy revolution that is changing the world.

Proton is using Recruitee recruitment platform for more effective hiring and better candidate experience. Your data will be kept confidential and not shared with any third parties.

Keep in mind that you will receive emails from careers@protonmail.recruitee.com email or other addresses on the protonmail.recruitee.com domain.