Senior Backend Engineer (Account)

Proton, the privacy‑first company behind services such as Proton Mail, VPN, Calendar, Drive and Pass, is looking for a Senior Backend Engineer to join its Account team. The team is responsible for the entire customer journey—from acquisition and sign‑up through account management, promotions and checkout—across all Proton products, serving more than 100 million users worldwide. In this role you will design and implement core backend services that power the most critical parts of Proton’s ecosystem. You will help shape a new, robust architecture that will be reused by every product, craft high‑performance APIs that enable mobile applications to deliver rich features quickly, and collaborate closely with product, design and other engineering groups to turn technical challenges into smooth user experiences. Daily work involves profiling, performance tuning and data‑driven decision making while ensuring the system remains scalable and reliable. The position requires proven backend development experience, a track record of building scalable, high‑throughput solutions, strong skills in profiling and performance optimisation, and demonstrated ability to lead an initiative from concept through production. Candidates must be customer‑focused, eager to learn continuously, and passionate about technology and usability