Senior Software Engineer, Firefox Security

• Advance Firefox's security architecture and cryptography stack, focusing on cryptographic protocols, WebPKI, and security-sensitive web APIs. • Design and implement web platform security features in collaboration with teammates and the broader web community. • Improve browser reliability, performance, and resource efficiency within a complex, multi-threaded browser environment.

• Bring strong software engineering experience with proficiency in C/C++ and a solid understanding of security principles, including cryptographic protocols and implementations. • Have experience building and maintaining software in large-scale or security-sensitive environments. • Demonstrate strong debugging and problem-solving skills in multi-threaded, cross-platform native applications, including performance and memory-related challenges. • Work effectively with distributed teams, communicate technical concepts clearly, and collaborate constructively to solve problems. • Show a growth mindset and willingness to deepen expertise in browser security, cryptography, and systems programming.

• Have familiarity with web technologies and interest or experience in Rust. • Be comfortable working within large, complex, multi-language codebases. • Bring experience contributing to web standards or interoperable browser implementations. • Have background in public key infrastructure or WebPKI.

• Contribute to improvements in Firefox's core security systems, with a focus on cryptographic protocols, WebPKI, and security-sensitive web APIs. • Help implement and maintain security features that support the evolution of public key infrastructure on the web. • Develop and ship web platform features in collaboration with teammates and the broader web community. • Contribute to standards-based, secure, and interoperable implementations across Firefox. • Investigate and resolve issues impacting stability, correctness, and performance. • Analyse and improve memory usage and efficiency within a complex, multi-threaded browser environment. • Partner with engineers across teams to identify, prioritise, and address security issues. • Participate in debugging, root cause analysis, and implementation of effective long-term solutions. • Participate in technical discussions, design reviews, and project planning for security-related initiatives. • Help evaluate tradeoffs and contribute to engineering decisions within your area of work.

• Receive generous performance-based bonus plans. • Access rich medical, dental, and vision coverage. • Benefit from generous retirement contributions with 100% immediate vesting. • Enjoy quarterly all-company wellness days. • Take country-specific holidays plus a day off for your birthday. • Receive a one-time home office stipend. • Use an annual professional development budget. • Receive a quarterly well-being stipend. • Take considerable paid parental leave. • Participate in the employee referral bonus programme. • Access additional benefits including life/AD&D, disability, and EAP (varies by country).

Mozilla Corporation is a non-profit-backed technology company that has shaped the internet for the better over the last 25 years. It makes pioneering brands like Firefox, the privacy-minded web browser, used by more than 225 million people worldwide each month. Wholly owned by the non-profit 501(c) Mozilla Foundation, Mozilla isn't beholden to shareholders — only to its mission to make the internet better for people.