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Mozilla

Contract Staff Software Engineer-Bug Burndown

Mozillaยทabout 7 hours ago

โฐ Full-time๐ŸŽฏ Lead / Principal๐Ÿ‡ฌ๐Ÿ‡ง UK๐Ÿ“… Oct 20, 2026

You will help reduce Firefoxโ€™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.

Market context

Measured from remote postings we have tracked ourselves โ€” not self-reported survey data.

What Lead / Principal Engineering roles in Europe pay

25th
$82k
Median
$130k
75th
$156k

Based on 682 comparable postings with disclosed salaries, last 12 months.

How Mozilla is hiring

Last 90 days
136 roles
Total tracked
483
Hiring across
11 job families

Tracked since June 2025.

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