The Performance Tools team builds frameworks and tools that help engineers measure and improve performance across Mozilla products. We’re a distributed team based in North America and Europe, supporting both internal Mozilla engineers and the broader web developer community through tools like the Firefox Profiler.

In this role, you will work on the user interface of the Firefox Profiler. This includes implementing interactive performance visualizations, handling large-scale performance data efficiently in the browser, and improving usability for engineers across Mozilla. You will collaborate with systems engineers, browser developers, and other teams working on performance.

What you’ll do

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.

What you’ll bring

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.
Experience working with performance visualization is a plus.
Familiarity with the Firefox Profiler or Chrome DevTools is a plus.
Commitment to our values:
- Welcoming differences
- Being relationship-minded
- Practicing responsible participation
- Having grit