Senior Software Engineer, WebAssembly Team
at Mozilla Corporation
Core Product-Firefox
Remote US, Remote Canada
The Opportunity

Are you excited about web technologies and the applications built on them that enrich users’ lives? Do you have a passion for learning how computers work at their lowest level? Are you interested in learning about compilers and programming languages?

We are looking for a skilled developer for our WebAssembly team, which develops the WebAssembly engine that powers high-performance experiences in the Firefox browser.   The team is distributed across the US, Canada and Europe, where our culture is focused on strong collaboration, teamwork, and a good work life balance.

What You Will Get To Do 

As a WebAssembly Engineer at Mozilla you’ll be instrumental in the continued advancement of the WebAssembly language and the Web platform at large.  Opportunities to learn innovative technologies abound, and working in the open is the norm. Responsibilities include writing code, tests, and specifications, while building prototypes, solving problems, analyzing data and improving performance.  You will have the opportunity to engage with the WebAssembly Working Group and community on standardization efforts. 

What You Bring 
  • Proficient with C++ or another systems programming language
  • Experience with WebAssembly, JavaScript VM’s or a strong interest in learning
  • Creative problem-solver, proficient at debugging and strong collaboration skills
  • Ability to learn a large and complex code base
  • A general strong interest in continued learning and improving your abilities
Bonus Points

We value a variety of voices. You don’t need to check every box on this list to apply. 

  • Knowledge of general systems architecture (such as x86, x64, ARM, ARM64, etc)
  • Experience in systems programming: compilers, garbage collectors, or virtual machines
  • Experience with performance analysis
  • Experience with internet standards such as WebAssembly CG or TC39
  • Interest in working on open source software

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: D


Req ID: R1964

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