Senior Software Engineer, Firefox Security

• Join Mozilla’s Firefox team as a Senior Software Engineer for Firefox Security, working fully remotely from the UK or Europe. • Design and ship security and hardening features for enterprise Firefox users. • Advance Firefox’s security architecture across multiple operating systems. • Improve core security mechanisms such as cryptographic protocols, WebPKI and security-sensitive web APIs. • Work on privilege isolation and trust boundaries in a large, multi-language codebase. • Help protect the 225 million people who use Mozilla’s products every month.

• Bring 3+ years of experience in low-level software engineering. • Write strong C and/or C++ code. • Show a solid understanding of security fundamentals. • Debug multithreaded, cross-platform native applications, including memory and performance issues. • Know web technologies such as HTML, CSS and JavaScript. • Work effectively in large, complex, multi-language codebases. • Collaborate with distributed teams and explain technical ideas clearly.

• Bring experience with Rust, or a strong interest in learning it. • Show experience with cryptographic protocols or WebPKI. • Bring experience building privilege isolation or sandboxing features. • Show experience building security features for enterprise users. • Bring experience working on browser engines.

• Design, implement, test and ship security and hardening features for enterprise users. • Build privilege isolation and move trust boundaries to strengthen Firefox’s security posture. • Improve cryptographic protocols, WebPKI and security-sensitive web APIs. • Investigate security issues across teams, find root causes and deliver robust fixes. • Resolve stability, performance and memory issues in a complex, multithreaded environment.

• Earn a generous performance-based bonus. • Get up to 26 weeks of fully paid parental leave for childbearing parents and 12 weeks for non-childbearing parents. • Receive generous retirement contributions with immediate vesting. • Enjoy quarterly all-company wellness days and a day off for your birthday. • Use up to $3,000 a year for professional development and a quarterly well-being stipend. • Get a one-time home office stipend and the latest hardware and software of your choice.

Mozilla Corporation is the non-profit-backed technology company behind Firefox, the privacy-minded web browser used by more than 225 million people each month. It is wholly owned by the non-profit Mozilla Foundation, so it answers to its mission rather than shareholders. Mozilla builds open-source software with over 1,000 staff in 30+ countries and thousands of volunteer contributors.