Senior Software Engineer, OS Integration

Mozilla · Remote (Canada)

New this week Posted 9 Nov 2026; checked 9 Nov 2026.

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About the role

Why Mozilla?

Mozilla Corporation is the non-profit-backed technology company that has shaped the internet for the better over the last 25 years. We make pioneering brands like Firefox, the privacy-minded web browser. Now, with more than 225 million people around the world using our products each month, we’re shaping the next 25 years of technology and helping to reclaim an internet built for people, not companies. Our work focuses on diverse areas including AI, social media, security and more. And we’re doing this while never losing our focus on our core mission – to make the internet better for people.

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 the OS Integration team

The OS Integration team ensures Firefox works well with the host operating system and environment. We’re a distributed team with expertise in Windows, macOS, and Linux-based operating systems. Our responsibilities include developing fixes and improvements for Firefox related to Windows, macOS, and Linux environments. This might include integration with a new OS feature or fixing an OS-specific user interface bug. Other responsibilities include native crash reporting, OS abstraction layers, sandboxing, hardening, updater, and enterprise DLP support.

About the role

As a member of the OS Integration team, you’ll develop fixes, improvements, and new features for Firefox. In many cases work may be cross-platform or have a cross-platform component. This role will include maintenance and development of the installer and updater of Firefox. You’ll contribute to the team through code review and discussion.

What you’ll do

Improve the quality of Firefox and other Mozilla products by debugging and fixing software defects, improving the browsing experience for hundreds of millions of users.

Contribute to new features and improvements.

Break down tasks and work with others to deliver solutions.

Collaborate with experienced software engineers.

Perform code reviews and provide technical direction.

Work with a geographically-distributed development team.

Interact with teams throughout the organization.

Strong knowledge of C and C++

Experience with desktop application development on Windows, macOS, or Linux with C++.

Knowledge of web technologies such as Javascript and HTML.

Knowledge of secure coding practices and memory safety concerns.

Strong problem-solving and debugging skills.

Written and verbal communication skills with a collaborative mindset.

Willingness to work effectively in a distributed team environment.

Installer and/or Updater development on any OS

Windows internals like the BITS server or MSIX packages

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

Continued in Mozilla’s original posting ↗.

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