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Senior Contract C++ / JavaScript Software Engineer Firefox (Browser Engine)

Mozilla· Firefox
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RemoteFull-timePosted 6d ago

About the role

Role focused on improving Session History coverage and Gecko correctness within the Firefox DOM Core team, by authoring and fixing tests, engaging in code review, and driving test coverage to improve reliability.

Responsibilities

  • Write Web-Platform tests to improve the coverage, and Gecko mochitests as needed
  • Fix the problems and pass the tests to improve the Gecko correctness
  • Work through code review with the relevant Gecko module owners and iterate to landing

Qualifications

  • Substantial experience in a browser-engine codebase or in automating for a browser-engine, ideally Firefox/Gecko
  • Solid Javascript and applying that language skill to write automated tests
  • Proficiency in and experience developing software in C++
  • Strong debugging skills in a mature large codebase
  • Comfort working in the open: public bugs, code review, and upstream landing

Skills

Required:Web-Platform testingJavaScriptC++DebuggingCode review / open source collaboration
Last updated Oct 21, 2026. Interested? Apply on the company site.

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