What you'll be doing

Design, build, and implement security and hardening features for enterprise users to strengthen Firefox’s security posture.
Advance Firefox’s security architecture across multiple operating systems by building privilege isolation and moving trust boundaries or improving core security mechanisms like cryptographic protocols, WebPKI, and security-sensitive web APIs.
Contribute to security initiatives by investigating issues, identifying root causes, and delivering robust, maintainable fixes.
Improve browser reliability and performance by diagnosing and resolving issues affecting stability, correctness, performance, and memory usage in a complex, multithreaded environment.

Requirements

3+ years of experience in low-level software engineering with strong proficiency in C and/or C++ and solid understanding of security fundamentals.
Experience diagnosing and resolving issues in multithreaded, cross-platform native applications, including memory and performance challenges.
Familiarity with web technologies (HTML, CSS, JavaScript) and interest or experience in Rust; ability to work effectively within large, complex, multi-language codebases.
Experience working with distributed teams and effective communication skills for conveying technical ideas clearly in writing and conversation.

Generous performance-based bonus plans applicable to all eligible employees.
Generous retirement contributions with 100% immediate vesting regardless of personal contributions.
Quarterly all-company wellness days for collective pauses.
Country specific holidays plus a day off for your birthday.
One-time home office stipend and annual professional development budget.
Quarterly well-being stipend and considerable paid parental leave.
Employee referral bonus program and additional benefits such as life/AD&D insurance, disability coverage, and Employee Assistance Programs, varying by country.