Senior Software Engineer, Firefox Security - Mozilla Corporation

Key Responsibilities

• Design, implement, and maintain security-critical components of the Firefox browser, including sandboxing, certificate handling, and exploit mitigation.
• Collaborate with product, UX, and QA teams to integrate security controls without degrading user experience.
• Conduct threat modeling, code reviews, and security audits to identify and remediate vulnerabilities.
• Develop automated testing frameworks and fuzzing pipelines to continuously validate the robustness of browser code.
• Mentor junior engineers and contribute to open‑source security initiatives within the Mozilla ecosystem.

Requirements

• 5+ years of professional software development experience, primarily in C++ and Rust.
• Deep understanding of modern browser security architecture, cryptographic protocols, and Linux system internals.
• Proven experience with security testing tools, fuzzing, static analysis, and vulnerability research.
• Strong problem‑solving skills, ability to work cross‑functionally, and a passion for open‑source collaboration.
• Excellent communication skills and a commitment to Mozilla’s mission of a healthier internet.