MozillaHiring

Senior Software Engineer, Firefox Security

  • Remote, Germany
  • Senior
  • Posted 2 weeks ago
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In one line

Build and harden security features in a widely used open-source web browser, working in C and C++ on a distributed team.

About the role

Security engineering sits at the core of the browser, covering privilege isolation, trust boundaries, cryptographic protocols and web APIs. The work also involves chasing down stability, memory and performance bugs in a large multi-language codebase.

At a glance

Pay
Not stated in the posting
Remote scope
Remote, Germany
Seniority
Senior
Skills
Rust, HTML, CSS, JavaScript, WebPKI
Posted
14 Oct 2026
Last checked
29 Oct 2026

What you will do

  • Design, test and ship security and hardening features aimed at enterprise users
  • Improve the browser's security architecture across operating systems, including privilege isolation and trust boundaries
  • Strengthen core mechanisms such as cryptographic protocols, WebPKI and security-sensitive web APIs
  • Investigate security issues with other teams, find root causes and deliver maintainable fixes

What they look for

  • Three or more years in low-level software engineering, strong C and/or C++ skills and a solid grasp of security basics
  • Familiarity with HTML, CSS and JavaScript, interest in Rust, and clear communication in distributed teams

Benefits

  • Performance-based bonus plans for eligible employees
  • Retirement contributions vested immediately, whether or not you pay in
  • Quarterly all-company wellness days and a day off for your birthday
  • One-time home office stipend and an annual professional development budget

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Claude

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Muse

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Message for Muse
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Prompt
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Questions about this job

Is this job fully remote, and from where?

The posting lists it as remote for people in Germany.

What does this job pay?

The posting does not state a salary, so there is no figure to quote.

What experience is needed?

It is a senior role. The posting asks for: three or more years in low-level software engineering, strong C and/or C++ skills and a solid grasp of security basics; familiarity with HTML, CSS and JavaScript, interest in Rust, and clear communication in distributed teams. Skills it names include Rust, HTML, CSS, JavaScript.

How do I apply with Keywordise AI?

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