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Software Engineer, DOM Core

· Job Posted January 08, 2026
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Job Description

Join the global DOM: Core team of engineers passionate about the Web. We are the team responsible for page navigation, document loading, event handling, user interaction, and text editing in Gecko, the engine behind Firefox. You will implement standardized APIs like DOM, HTML, Events, Editor, and Clipboard. You will push the boundaries of what the Web is capable of. Your responsibilities will include writing code, tests, as well as building prototypes, solving problems, while continuously learning and growing as an engineer.

Job Responsibility

  • Improve the DOM, HTML, editing, user interaction capabilities of our Web engine, with a focus on performance, Web compatibility, and standards correctness
  • Read and implement API specifications, as well as contributing to the standards process by raising issues or participating in discussions
  • Develop and debug in a multi-language, multi-threaded and multi-process code base
  • Work primarily in C++ and write tests largely with HTML and JavaScript
  • Collaborate with a geographically distributed development team

Requirements

  • Proficiency in and experience developing software in C++
  • Ability to learn a large and complex code base quickly
  • Comfortable contacting people and driving discussions
  • Motivated to learn new tools and techniques for improving existing software
  • Familiarity with one or more of the following, or ability to pick them up in a timely manner: Multi-process architecture
  • Debugging memory usage or performance profiling
  • The modern Web technologies (JavaScript, HTML, and/or CSS)
  • Commitment to our values: Welcoming differences
  • Being relationship-minded
  • Practicing responsible participation
  • Having grit

What we offer

  • 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)
  • Flexible work environment
  • Industry-leading paid parental leave
  • Reimbursement for professional development (up to $3,000/year)
  • A work setup including the latest hardware and software of your choice
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