← All jobs
Mozilla

Contract Staff Software Engineer-Bug Burndown

Remote UK
Level
Staff
Work type
Remote · UK only

Not stated in the posting: salary, visa.

Open. First seen 20 October 2026.

Apply on the company's site →

About the role

You will help reduce Firefox’s WebCompat bug backlog by finishing or verifying the diagnosis of the long tail of site-breakage bugs, and by writing interventions or simple fixes (often with AI assistance). You turn a large queue of reported breakages into diagnosed, actionable, or fixed bugs.

Responsibilities

  • Finish diagnosing, or verify the diagnosis of, long-tail WebCompat bugs.
  • Write WebCompat interventions where appropriate.
  • Write simple fixes (AI-assisted) and land them.
  • Reproduce and triage incoming site-breakage reports.

Required qualifications

  • Solid web development (HTML, CSS, JavaScript) and comfort debugging real-world site breakage.
  • Fluent with browser devtools and cross-browser diagnosis.
  • Comfortable using AI tooling to speed up diagnosis and fixes.

Preferred

  • Gecko knowledge is a strong plus (but can be taught).
  • Prior WebCompat or web-standards experience.

What this role asks for

Particular to this role

HTML

Rare in Mozilla's other 106 open postings.

Compared with Mozilla's other open jobs.

The team: Firefox HIRES STEADILY

This role is one of 62 open in Firefox. 35 were posted in the last 30 days and the oldest in February: a team that hires all year rather than one being built.

WHAT THE TEAM WORKS WITH, ACROSS ITS POSTINGS

C++ (37 of 62), JavaScript (37 of 62), Rust (32 of 62), Python (29 of 62), CI/CD (18 of 62), TypeScript (18 of 62), CSS (17 of 62)

OTHER ROLES ON THIS TEAM

From the team and dates on Mozilla's own job board.

Similar jobs

Is this your posting? Email info@careerholo.com to have it removed.