Fullstack Engineer – MSA Team

About the role

Proton is looking for a Fullstack Engineer to join its MSA (Mail, Spam & Abuse) team. The team builds highly‑scalable systems that protect millions of users from spam, abuse, and security threats while also delivering new AI‑driven products such as Wallet, Lumo AI, and Meet.

Key responsibilities

• Design, develop, and maintain full‑stack features for mail delivery, spam filtering, and account‑security services.
• Integrate machine‑learning models and AI components into production pipelines.
• Ensure high availability, performance, and security of real‑time decision‑making systems.
• Collaborate with autonomous, cross‑functional teammates to own the end‑to‑end product lifecycle.
• Participate in code reviews, testing, and continuous‑delivery processes.

Required profile

• Proven experience building production‑grade software that handles large‑scale traffic.
• Comfort working in a fast‑moving, resource‑constrained environment.
• Strong analytical mindset and ability to solve complex, multidisciplinary problems.

Required skills

What we offer

• Opportunity to work on privacy‑focused products used by hundreds of millions worldwide.
• Flat organisational structure with high autonomy and impact.
• Collaborate with world‑class researchers, engineers, and former Olympiad winners.