About the company
Mozilla Corporation is the non-profit-backed technology company behind Firefox. We are shaping the next 25 years of technology, focusing on AI, social media, security, and more.
About this team and role
Mozilla is seeking experienced browser engineers to join a small team exploring new applications of browser technology. The work combines deep systems engineering, rapid experimentation, and close collaboration across technical disciplines. This is a hands-on individual contributor role with ownership of engine-level investigations and implementation.
Responsibilities
- Design and implement experiments within browser engine subsystems.
- Investigate how internal data structures and execution behavior affect performance, correctness, and developer tool interfaces.
- Evaluate ways to represent and expose browser state efficiently and accurately.
- Prototype engine capabilities that support reliable programmatic interaction with web content.
- Instrument browser behavior and evaluate changes against repeatable tasks.
- Profile overhead introduced by new capabilities and pursue improvements.
- Use AI tools to accelerate coding and analysis, verifying output through debugging, tests, and measurement.
Requirements
- Deep hands-on expertise in at least one browser engine subsystem: DOM and Web APIs, layout and rendering, accessibility, JavaScript runtimes, or networking and process architecture.
- Strong proficiency in C++ or Rust.
- Experience navigating a large systems codebase.
- Practical knowledge of memory ownership, concurrency, object lifetimes, and performance debugging.
- Ability to build JavaScript and scripting tools for measurement.
- Strong understanding of web platform behavior and compatibility.
- Experience with profiling, tracing, regression tests, or conformance tests.
- Curiosity about AI agents and willingness to work with agent harnesses and coding tools.
Nice to have
- Contributions to Gecko, Servo, Blink, WebKit, or another browser engine.
- Experience maintaining an open-source project.
- Technical leadership in a small team building a new product.
- Experience with accessibility infrastructure, browser security, profiling, or automated evaluation of agent workflows.
Conditions
- Generous performance-based bonus plans.
- Rich medical, dental, and vision coverage.
- Generous retirement contributions with 100% immediate vesting.
- Quarterly all-company wellness days.
- 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).