Senior Software Engineer Protocols (m/w/x)

About us

Threema is the world's best-selling secure messenger for both private users and businesses. Since 2012, we have been relentlessly committed to ensuring that our users can communicate without worrying about their privacy. Our growing user base includes millions of private customers and thousands of companies and organisations from all over the world.

Your Tasks

Are you excited by developing application protocols for interactions between mobile apps and backend services? Are you interested in the security aspects of interaction flows? Are you an enthusiastic Rustacean? Then this position is just right for you.

As an engineer in the protocols team, you will help us to further develop the core of Threema and contribute to the effective privacy protection of millions of people.

• Build a deep understanding of the existing application and network protocols of the Threema ecosystem

• Design and specify new application and network protocols

• Implement protocol flows in libthreema, a Rust library that serves as the common core of future Threema apps

• Develop libthreema bindings for Android (Kotlin), iOS (Swift) and desktop (TypeScript / WASM)

• Perform code reviews within the development team

Your Skills

Technical experience:

• Experience with the design and implementation of network and application protocols

• Extensive experience in software development, at least 1 year of practical experience with Rust

• Enjoy high quality code (automated tests, linter, etc.)

• Bonus points for experience with secure programming techniques, cryptography, protocol buffers, sans I/O, mobile apps, algorithms and data structures

Soft Skills

• High level of awareness when it comes to security and privacy issues.

• Strong sense of responsibility, precise way of working

• Ability to analyse complex problems and domains and to find creative solutions

• You can explain technical concepts clearly and precisely

• You can break down requirements and long-term goals into clear work packages

• You are willing to familiarize yourself with new technologies and concepts and constantly learn new things

• Good written and spoken German and English (at least B2)

We are also happy to accept applications from people who meet many but not all of these criteria.

What we offer

Working Environment

• A young, motivated team (±60 employees) with uncomplicated communication

• Work-life balance: flexible working hours, home office option on up to two days per week, up to two home office weeks per year

Benefits

• Free budget for computer/workstation (macOS or Linux)

• Public transport discount or car park

  • Electric car charging facility

• Free use of the company's own fitness room incl. fitness trainer once a month

• Table tennis table

• Professional massage once a month

• Free coffee with a portafilter machine and coffee beans from the region

• Regular company events and after-work drinks