Senior Software Engineer (Firefox Security)

Join Mozilla as a Senior Software Engineer focused on Firefox Security. In this role, you will design, build, and implement security features for enterprise users, advance Firefox's security architecture across multiple operating systems, contribute to security initiatives, and improve browser reliability and performance. Enjoy a comprehensive benefits package, including health and wellness coverage, mental health support, generous time off, parental leave, financial incentives, learning and development opportunities, and more.

GBP 66,000 - 87,000

Responsibilities

• Design, implement, test, and ship cutting-edge security features that strengthen Firefox’s security posture.
• Contribute to and drive cutting-edge improvements to Firefox’s core security posture, by building privilege isolation and moving trust boundaries.
• Work across teams to investigate security issues, identify root causes, and deliver robust, maintainable fixes.

Requirements

• Debugging and problem-solving skills: Experience diagnosing and resolving issues in multithreaded, cross-platform native applications, including memory and performance challenges
• Web platform and modern systems experience: Familiarity with web technologies (HTML, CSS, JavaScript) and interest or experience in Rust; ability to work effectively within large, complex, multi-language codebases
• Systems programming experience and security knowledge: 3+ years of experience in low-level software engineering, strong proficiency in C and/or C++, and a solid understanding of security fundamentals
• Effective collaboration and communication: Experience working with distributed teams and communicating technical ideas clearly in writing and conversation