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# Software Engineer, Firefox Security

- **Company:** Mozilla Corporation
- **Location:** France (Remote available)
- **Experience:** Expert
- **Contract:** Permanent contract
- **Skills:** HTML, JavaScript (Programming Language), C++ (Programming Language), Cascading Style Sheets (CSS), Cyber Security, Software Debugging, Memory Management, Cryptographic Protocols, Firefox, System Programming, Web Platforms, Multithreading, Web Technologies, Web Api
- **Published:** October 15, 2026
- **Apply:** https://job-boards.greenhouse.io/mozilla/jobs/8282248

## About the Role

* 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.
 * 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.
 * Effective collaboration and communication: Experience working with distributed teams and communicating technical ideas clearly in writing and conversation.

## Description

* Design, build and implement security and hardening features for enterprise users: Design, implement, test, and ship cutting-edge security features that strengthen Firefox's security posture.
 * Advance Firefox's security architecture across multiple operating systems: Contribute to and drive cutting-edge improvements to Firefox's core security posture, by building privilege isolation and moving trust boundaries or Strengthen Firefox's security architecture: Improve Firefox's core security mechanisms including cryptographic protocols, WebPKI, and security-sensitive web APIs.
 * Contribute to our security initiatives: Work across teams to investigate security issues, identify root causes, and deliver robust, maintainable fixes.
 * Improve browser reliability and performance: Diagnose and resolve issues affecting stability, correctness, performance, and memory usage in a complex, multithreaded environment.