Staff Browser Engine Engineer – New Products

Mozilla; Toronto; On-site; CAD 145,000 - 170,000; Full time

Benefits offered by this job

Bonus plans

Medical, dental, vision coverage

Retirement contributions with vesting

Wellness days

Holidays plus birthday day off

Home office stipend

Professional development budget

Well-being stipend

Parental leave

Referral bonus program

Other benefits

Job summary

Mozilla is seeking experienced browser engineers to join a small team exploring new applications of browser technology. You will perform engine-level investigations and implement changes, working closely with the technical lead.

You’ll prototype capabilities, measure performance, and ensure changes are robust across workloads and web content. This hands-on role emphasizes deep systems engineering and collaboration.

Qualifications

• Expertise in at least one browser engine subsystem (e.g., DOM/Web APIs, rendering, JS runtimes).
• Strong programming skills in C++ or Rust and large codebase navigation.
• Experience with memory ownership, concurrency, and performance debugging.
• Ability to hypothesize, prototype, and measure results in complex systems.
• Familiarity with profiling, tests, regression suites, and conformance checks.

Responsibilities

• Design and implement experiments within browser engine subsystems.
• Investigate internal data structures and execution behavior for performance and correctness.
• Prototype engine capabilities enabling programmatic interaction with web content.
• Instrument browser behavior and compare changes against repeatable tasks; document results.

Skills

Browser engine subsystem

C++/Rust

Memory ownership

Concurrency

Performance debugging

Web platform understanding

AI tool familiarity

Tools

None

Job description

Mozilla is seeking experienced browser engineers to join a small team exploring new applications of browser technology. You will perform engine-level investigations and implement changes, working closely with the technical lead.

You’ll prototype capabilities, measure performance, and ensure changes are robust across workloads and web content. This hands-on role emphasizes deep systems engineering and collaboration.