Frontend Senior Software Engineer

Requirements

• 5+ years of experience in JavaScript/TypeScript, React, Redux, and browser-based UI development.
• A strong background in building complex, interactive UIs that manage large data sets efficiently.
• Knowledge of profiling, performance tooling, and testing.
• Knowledge of frontend testing frameworks (e.g., Jest, React Testing Library) and best practices in maintainable UI codebases.
• Strong and respectful communication skills and ability to collaborate across engineering teams.

Nice to Haves

• Experience working with performance visualization is a plus.
• Familiarity with the Firefox Profiler or Chrome DevTools is a plus.

What You'll Be Doing

• Design and develop modern, interactive UI components for the Firefox Profiler using TypeScript, React, Redux, and related web technologies.
• Build high-performance, scalable, accessible, and maintainable user interfaces that visualize complex performance data.
• Engage with other Firefox engineers to help them learn how to use our tools efficiently, and develop projects to serve them better.
• Engage with the performance team efforts such as bug triage and strategy.
• Promote and encourage the use of our performance tools within and beyond Mozilla by writing and talking about them.
• Engage with our community and mentor volunteers contributing to the codebase.

Perks and Benefits

• Generous performance-based bonus plans to all eligible employees - we share in our success as one team.
• Rich medical, dental, and vision coverage.
• Generous retirement contributions with 100% immediate vesting (regardless of whether you contribute).
• Quarterly all-company wellness days where everyone takes a pause together.
• Country specific holidays plus a day off for your birthday.
• One-time home office stipend.
• Annual professional development budget.
• Quarterly well-being stipend.
• Considerable paid parental leave.
• Employee referral bonus program.
• Other benefits (life/AD&D, disability, EAP, etc. - varies by country).