Contract Software Engineer - DOM Core Firefox/Gecko
mozilla· Firefox
About this role
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.
Frequently Asked Questions
Is the salary disclosed for the Contract Software Engineer - DOM Core Firefox/Gecko position at mozilla?
The salary for this Contract Software Engineer - DOM Core Firefox/Gecko role at mozilla is not publicly listed. Click "Apply Now" to learn more about the compensation package on their official careers page.
Is the Contract Software Engineer - DOM Core Firefox/Gecko job at mozilla remote?
Yes, this Contract Software Engineer - DOM Core Firefox/Gecko position at mozilla is remote, with team members based in Remote France; Remote Germany; Remote UK. You can work from home or anywhere in the supported regions.
Which team or department does the Contract Software Engineer - DOM Core Firefox/Gecko at mozilla belong to?
This Contract Software Engineer - DOM Core Firefox/Gecko position is part of the Firefox department at mozilla. See the full job description for more information about the team structure and responsibilities.
How do I apply for the Contract Software Engineer - DOM Core Firefox/Gecko position at mozilla?
Click the "Apply Now" button on this page. You will be redirected to mozilla's official application portal hosted on greenhouse where you can submit your application directly.
When was the Contract Software Engineer - DOM Core Firefox/Gecko job at mozilla posted?
This Contract Software Engineer - DOM Core Firefox/Gecko position at mozilla was posted on Sep 22, 2026. Apply as soon as possible — early applications are often reviewed first.
Contract Software Engineer - DOM Core Firefox/Gecko
mozilla
You'll be redirected to mozilla's official application page on Greenhouse.