Senior Systems Software Engineer Remote UK

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:

The Performance Tools team builds frameworks and tools that help engineers measure and improve performance across Mozilla products. We’re a distributed team based in North America and Europe, supporting both internal Mozilla engineers and the broader web developer community through tools like the Firefox Profiler.

In this role, you will be responsible for low-level programming of the Firefox Profiler and other tools. Your focus will be on delivering an effective toolset for Firefox developers looking to track down and seize every opportunity to improve the quality of experience for our users. You will work closely with performance experts to identify and surface the most valuable measurements across a variety of platforms.

What you’ll do:

• Expand the breadth of data captured by the Firefox Profiler without compromising on performance.
• Engage with the performance team efforts such as bug triage and strategy.
• Engage with other Firefox engineers to help them learn how to use our tools efficiently, and develop projects to serve them better.
• Promote and encourage the use of our performance tools within and beyond Mozilla by writing and talking about them.
• Engage with our community and mentor volunteers contributing to the codebase.

What you’ll bring:

• 5+ years of experience in systems software engineering using C++.
• 1+ year of experience in Rust.
• Expertise in at least one of the following operating system APIs and familiarity with the others: Windows/Linux/macOS/Android.
• Experience working on and debugging large multi-threaded applications and memory management.
• Strong and respectful communication skills and ability to collaborate across engineering teams.
• 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 stipend
• Considerable 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 hiringaccommodation@mozilla.com 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.