Senior Software Engineer, Windows Integration
at Mozilla Corporation
Core Product-Firefox
Remote US, Remote Canada, Berlin Office

The OS integration team is a cross-disciplinary team in charge of improving and maintaining Firefox on its various supported operating systems. Among other responsibilities, the team leads the various compiler (Rust, WASM sandboxing, Clang, LLVM, etc) integrations, crash investigation and security hardening efforts.

As a Senior Software Engineer in OS integration you will:

  • Investigate low-level systems programming issues on the Windows platform and assist our other specialists with your platform specific expertise.
  • Track upstream development of Rust, Clang and LLVM and monitor performance and compatibility with our code base. Investigate regressions and cooperate with upstream to contribute improvements.
  • Research new software tooling from both industry and academia, such as GWP-Asan and RLBox, and make it suitable for deployment in our products.
  • Manage the integration of the various compilers and tools in our infrastructure.
  • As a result of your input, Firefox will become a faster, more secure and more stable product that is easier to develop and built using state of the art tooling and technologies!
  • Collaborate with other teams by providing code review and technical direction.
  • Work with a geographically-distributed development team.

You should possess the following skills:

  • Experience with compilers, executable and library formats, and related tools.
  • Experience with low-level systems programming on Windows. 
  • You possess a solid understanding of C/C++.
  • You are an excellent communicator and have participated effectively on a distributed team.
  • You’re pragmatic about how to move things forward in specific time frames including trade-offs and safeguards when implementing new functionality.

Bonus points for

  • Some Rust experience would be a bonus.
  • Additional Linux, Android and/or macOS experience is a bonus, particularly with low level systems programming or operating system internals.
  • Experience with security hardening or software exploitation techniques will set you apart.

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 orientations, 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.

Group: C


Why Mozilla?

At Mozilla, we’re serving humanity—by maintaining a safe, open internet—while also helping the individual humans employed here to reach their personal and professional goals. With a relatively small team serving hundreds of millions of people, a culture of exploration, and a commitment to mentorship, opportunities abound to learn and grow at Mozilla.

Our values drive our actions

  • Purpose is built into our work, with our mission driving every decision
  • We challenge assumptions, the status quo, ourselves, and each other
  • We are transparent: in our code, our business partnerships, and our everyday interactions
  • We seek out people from diverse backgrounds and with perspectives different from our own
  • We pair purpose with performance and put people ahead of profit

Our impact is global

  • 700+ paid staff from over 30 countries
  • Thousands of volunteer contributors across six continents
  • 9 global offices: Mountain View, San Francisco, Portland, Vancouver, Toronto, Paris, London, Berlin, and Beijing
  • Hundreds of home offices globally

Our benefits are world-class

  • Flexible work environment (nearly half of Mozillians work remotely)
  • Industry-leading paid parental leave (up to 26 weeks of fully paid leave for childbearing parents and up to 12 weeks for non-childbearing parents)
  • Reimbursement for professional development (up to $3,000/year)
  • A work setup including the latest hardware and software of your choice