4 hours ago
Remote, CanadaStaff+
Responsibilities
- Design and implement experiments within browser engine subsystems.
- Investigate browser data structures, execution behavior, document structure, layout, navigation, and event handling.
- Prototype engine capabilities that support reliable programmatic interaction with web content.
- Instrument browser behavior and evaluate performance and correctness using repeatable tasks.
- Profile overhead, isolate the effects of changes, and document both successful and unsuccessful experiments.
- Use AI tools, agent harnesses, debugging, tests, and measurement to accelerate coding and analysis.
- Collaborate with technical leads and contribute to technical direction for new products.
Requirements
- Deep hands-on expertise in at least one browser engine subsystem, such as DOM and Web APIs, layout and rendering, accessibility, JavaScript runtimes, or networking and process architecture.
- Strong proficiency in C++ or Rust and 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 exercising and measuring browser behavior.
- Experience investigating unfamiliar code, forming hypotheses, building prototypes, and interpreting results.
- Strong understanding of web platform behavior, compatibility, document structure, script execution, rendering, and user interaction.
- Experience with profiling, tracing, regression tests, or conformance tests.
- Curiosity about AI agents and willingness to work directly with agent harnesses and coding tools.
- Contributions to Gecko, Servo, Blink, WebKit, or another browser engine are a plus.
- Open-source project maintenance, technical leadership, accessibility infrastructure, browser security, profiling, or automated evaluation of agent workflows are preferred.
Benefits
- Performance-based bonus plans for eligible employees.
- Medical, dental, and vision coverage.
- Retirement contributions with immediate vesting.
- Quarterly company wellness days, country-specific holidays, and a birthday day off.
- One-time home office stipend and annual professional development budget.
- Quarterly well-being stipend and paid parental leave.
- Employee referral bonus program and additional benefits varying by country.
- Remote role, as indicated by the #LI-REMOTE designation.
Tech Stack
Categories
About Mozilla
Mozilla builds open-source internet software, best known for the Firefox web browser, plus privacy tools like a VPN, password manager, and identity services. Its products are largely free and monetized through search partnerships and paid subscriptions, serving consumers, developers, and enterprises building for the web. Founded in 2005 and headquartered in San Francisco, Mozilla Corporation is wholly owned by the non-profit Mozilla Foundation.