Software Engineer, DOM Core

The Mozilla Corporation is wholly owned by the non-profit 501(c) Mozilla Foundation. This means we aren’t beholden to any shareholders — only to our mission. Along with thousands of volunteer contributors and collaborators all over the world, Mozillians design, build and distribute open-source software that enables people to enjoy the internet on their terms.

About this team and role:

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.

What you’ll do:

• 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
• Collaborate with a geographically distributed development team. Working in the open is the norm

What you’ll bring:

• 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
• Commitment to our values:
• Being relationship-minded
• Having grit

What you’ll get:

• Generous performance-based bonus plans to all eligible employees - we share in our success as one team
• Rich medical, dental, and vision coverage
• Generous retirement contributions with 100% immediate vesting (regardless of whether you contribute)
• Quarterly all-company wellness days where everyone takes a pause together
• Country specific holidays plus a day off for your birthday
• One-time home office stipend
• Quarterly well-being stipendConsiderable paid parental leave
• Employee referral bonus program
• Other benefits (life/AD&D, disability, EAP, etc. - varies by country)

About Mozilla

Mozilla exists to build the Internet as a public resource accessible to all because we believe that open and free is better than closed and controlled. When you work at Mozilla, you give yourself a chance to make a difference in the lives of Web users everywhere. And you give us a chance to make a difference in your life every single day. Join us to work on the Web as the platform and help create more opportunity and innovation for everyone online.

Commitment to diversity, equity, inclusion, and belonging

Mozilla understands that valuing diverse creative practices and forms of knowledge are crucial to and enrich the company’s core mission. We encourage applications from everyone, including members of all equity-seeking communities, such as (but certainly not limited to) women, racialized and Indigenous persons, persons with disabilities, persons of all sexual orientation s, gender identities, and expressions.

We will ensure that qualified individuals with disabilities are provided reasonable accommodations to participate in the job application or interview process, to perform essential job functions, and to receive other benefits and privileges of employment, as appropriate. Please contact us at to request accommodation.

We are an equal opportunity employer. We do not discriminate on the basis of race (including hairstyle and texture), religion (including religious grooming and dress practices), gender, gender identity, gender expression, color, national origin, pregnancy, ancestry, domestic partner status, disability, sexual orientation, age, genetic predisposition, medical condition, marital status, citizenship status, military or veteran status, or any other basis covered by applicable laws. Mozilla will not tolerate discrimination or harassment based on any of these characteristics or any other unlawful behavior, conduct, or purpose.