Senior Contract C++ / JavaScript Software Engineer Firefox (Browser Engine)
MozillaRemote · FR
At a glance
- Location
- Remote · FR
- Workplace
- Remote
- Pay
- Not published by the employer
- Employment type
- Contract
- Experience
- Not stated
- Education
- No degree requirement stated
- Job family
- Engineering
- Seniority
- Senior
- Posted by employer
- 20 October 2026
- Last verified open
- 23 October 2026
- Work from
- FR
- Region and country
- FR
- Team
- Firefox
- Listed via
- Greenhouse
What the employer wrote
The role
You will help the Firefox DOM Core team improve the health of the Session History area. You will write tests to improve the coverage; you will fix tests and/or problems to improve the Gecko correctness.
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
Definition of done
Improved Session History test coverage and code correctness in Gecko, measured by passed test cases, allowing the team’s senior engineers to focus on security, performance and strategic projects.
Required 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 larget codebase.
• Comfort working in the open: public bugs, code review, and upstream landing.
Preferred
• Prior contributions to Gecko or another major browser engine.
• Familiarity with web standards and Web Platform Tests.
Where this record came from
Read from Mozilla's own Greenhouse job board on , and last confirmed still open on . The employer published it on 20 October 2026. Jobsearch.ing did not write, edit or rank this posting, and does not vet the employer. View the original posting.