Strategic Overview
Senior Contract C++ / JavaScript Software Engineer Firefox (Browser Engine) at Mozilla is a dev opportunity centered on the specialist responsibilities and outcomes described in the employer's listing.
The published role emphasizes work such as 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.
The role is listed for Germany with remote working arrangement, giving candidates the practical context needed to assess fit before applying. Relevant signals in the listing include QA & Testing, Senior.
Key information at a glance
About This 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.
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.
Key Responsibilities & Objectives
- 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
Required Qualifications & Candidate Blueprint
- 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++.
Preferred Qualifications
- Prior contributions to Gecko or another major browser engine.
- Familiarity with web standards and Web Platform Tests.
Salary & Benefits
The available source data does not publish a numerical salary range for this opening. We do not estimate or substitute third-party figures.
Full Job Description
The following is the complete job description supplied by the source. We sanitize unsafe markup and remove external links, but do not shorten or rewrite the employer's source content.
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.
Editor’s Market Perspective (Our Custom Analysis)
Why This Position Matters
This dev opening is a useful opportunity for candidates whose experience matches QA & Testing, Senior. Its strongest career signal is the scope of the work itself — particularly Write Web-Platform tests to improve the coverage, and Gecko mochitests as needed — rather than a generic title alone.
Resume & Application Strategy
For the application, mirror the employer's language where it truthfully matches your background: foreground QA & Testing, Senior, quantify outcomes from comparable work, and place the most relevant experience near the top of the resume. If the listing specifies tools, platforms, leadership scope, or domain experience, use those exact terms in context instead of presenting an unrelated keyword list.
We organize source-provided information into this independent job-seeker overview. Compensation is shown only when the source provides it; the official listing remains the authority for current requirements and application instructions.