Senior Performance Software Engineer
at Mozilla Corporation
Team:
Core Product-Firefox
Locations:
Remote US, Remote Canada

The Mozilla Firefox Performance team is a community of engineers who care deeply about delivering the fastest browser possible. We are the team responsible for making all parts of the browser go fast.

Our team is geographically-distributed, and working in the open is the norm. We contribute to the code driving the Firefox browser on a number of platforms - Windows, Android, Linux, and macOS. Our focus is on finding and fixing things that slow down the browser as well as helping other teams write fast and reliable code to make Firefox excellent for users.

Do you value curiosity and enjoy finding a needle in a haystack? Do you approach problems by looking at the system as a whole? Do you like making things blazingly fast? If so, we’d love to hear from you.

What you'll do:

  • Write code and tests, build prototypes, tackle problems, profile and analyze performance bottlenecks
  • Learn about a wide variety of problems and solutions across a large, mature codebase (ex: what can slow things down when you have old code talking to new code and what can we do about it?)
  • Use several programming languages (e.g., JavaScript, C++, Kotlin, Rust, Python) and techniques to fix performance issues
  • Help to educate engineers on other teams about writing more performant code through code reviews, giving talks, and/or writing documentation
  • Work with driven, committed team members to help bring the Open Web to millions of people

Your Profile:

  • BS/MS in CS, CE or 5+ years relevant work experience
  • You have a proven understanding in programming performance critical systems or applications using languages such as C/C++, Java, or Rust
  • You have experience using a performance profiler
  • You take an experimental and measured approach to solving problems (measurement, and using experiments to diagnose an issue or prove out a solution)
  • Strong debugging skills in analyzing performance bottlenecks
  • An interest and ability to work in a distributed team (which requires good asynchronous written communication skills as well as good verbal communication skills)

Bonus points if you have any of the following:

  • Systems experience (multithreading and concurrency, disk I/O, CPU, etc)
  • Experience optimizing websites using metrics, for example Web Vitals
  • Familiarity with Android or Windows OS application programming, profiling and debugging
  • A deep understanding of statistics
  • Experience working with modern web development workflows, tools, and programming languages (e.g. JavaScript, React, Preact, cloud services and hosting solutions)

We value a variety of voices on the Performance Team at Mozilla. You don't need to check every box on this list to apply.

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 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.

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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