58K–77K EUR / year
Senior Software Engineer, Firefox Security
OtherRemote — Spain
Published on 2026-10-14
These details were extracted automatically from the original listing. They may not be complete or fully up to date — it's worth checking the original job post.
About this role
Build and ship security and hardening features for Firefox, with a focus on enterprise users. Improve browser security architecture across operating systems while addressing reliability, performance, and memory challenges.
About the company
Mozilla builds open-source products and technologies, including Firefox, that prioritize privacy, security, and an open internet.
Stack
CC++RustHTMLCSSJavaScriptWebPKI
What you'll do
- Design, implement, test, and ship Firefox security and hardening features
- Improve privilege isolation and trust boundaries across operating systems, or strengthen cryptographic protocols, WebPKI, and security-sensitive web APIs
- Investigate security issues across teams, identify root causes, and deliver maintainable fixes
- Diagnose and resolve stability, correctness, performance, and memory issues in a multithreaded browser
What we're looking for
- 3+ years of low-level software engineering experience
- Strong proficiency in C and/or C++ and solid security fundamentals
- Experience debugging multithreaded, cross-platform native applications, including memory and performance issues
- Familiarity with web technologies and ability to work in large, complex, multilingual codebases
- Clear technical communication and experience collaborating with distributed teams
Nice to have
- Interest or experience in Rust
Benefits
- Performance-based bonus plan
- Retirement contributions with immediate vesting
- Quarterly company wellness days
- Country-specific holidays and a birthday day off
- One-time home office stipend
- Annual professional development budget
- Quarterly well-being stipend
- Paid parental leave