Senior Software Engineer, Firefox Security

• Design, implement, test, and ship security and hardening features that strengthen Firefox’s security posture for enterprise users
• Contribute to and drive improvements to Firefox’s core security architecture across multiple operating systems, including privilege isolation and moving trust boundaries
• Improve Firefox’s core security mechanisms, including cryptographic protocols, WebPKI, and security-sensitive web APIs
• Work across teams to investigate security issues, identify root causes, and deliver robust, maintainable fixes
• Diagnose and resolve issues affecting stability, correctness, performance, and memory usage in a complex, multithreaded environment

• 3+ years of experience in low-level software engineering
• Strong proficiency in C and/or C++
• Solid understanding of security fundamentals
• Experience diagnosing and resolving issues in multithreaded, cross-platform native applications
• Experience addressing memory and performance challenges
• Familiarity with web technologies: HTML, CSS, and JavaScript
• Interest or experience in Rust
• Ability to work effectively within large, complex, multi-language codebases
• Experience working with distributed teams
• Ability to communicate technical ideas clearly in writing and conversation

• Generous performance-based bonus plans to all eligible employees - we share in our success as one team
• Generous retirement contributions with 100% immediate vesting (regardless of whether you contribute)
• Quarterly all-company wellness days where everyone takes a pause together
• Country specific holidays plus a day off for your birthday
• One-time home office stipend
• Annual professional development budget
• Quarterly well-being stipend
• Considerable paid parental leave
• Employee referral bonus program
• Other benefits (life/AD&D, disability, EAP, etc. - varies by country)