Senior Firefox Test Engineer, Ecosystem
at Mozilla Corporation
Core Product-Firefox
Remote US, Remote Canada, Remote Germany

The Company

A lot of companies say they’re “mission-driven”. Our unique corporate structure guarantees that every decision we make upholds our mission: to make sure the internet stays available, safe, and welcoming to everyone. Beholden to neither shareholders nor investors, Mozilla Corporation is wholly owned by the not-for-profit Mozilla Foundation.

Along with 20,000+ volunteer contributors and collaborators all over the world, Mozilla Corporation’s staff designs, builds, and distributes software that allows people to enjoy the internet on their own terms. Our flagship product — the Firefox browser — has expanded into a family of products that protects users and alerts them of risks.

The Opportunity

The Ecosystem Test Engineering team is passionate about helping Mozilla ship well-tested, high quality products. You will work alongside product and engineering groups and advance automated testing efforts that are key to building engaging and inclusive products. 

We’re a part of the Mozilla Firefox Engineering team; our community of engineers is geographically-distributed, and working in the open is the norm. We contribute to the code driving Firefox browser services in a number of languages, including Rust, Python, and JavaScript. 

Our team is invested in fostering a culture of learning, growing strong leaders and building a collaborative work environment. We want to raise the performance bar with every hire and promotion. You could be the next great thing to happen to our team.

What You'll Get To Do

  • Design, develop and maintain test strategies for large scale services.
  • Write, run, and maintain automated tests and identify gaps in test coverage.
  • Work collaboratively with many teams including product, design, UX, developers, operations, and data engineers.
  • Help prioritize product testing and risk management, advocate for building robust systems and practices, and represent our end-users’ best interests.
  • Ensure our ship process is fast, repeatable, and dependable by managing the logistics of shipping software including building and maintaining our CI pipeline.
  • Build tooling and frameworks to make testing easier and improve observability.
  • Contribute towards building a healthy team culture, nurture and mentor junior engineers, be invested in your growth as well as your peers.
  • Be an opinionated advocate for Testing and Quality.

Minimum Qualifications

  • 5+ years of experience in a software automation engineering role (SDET, test engineer, etc).
  • 2+ years experience in building and testing scalable services (Services & API testing, load testing, etc).
  • Proficiency in Python and industry standard automation tools, including pytest.
  • Knowledge and ability to set up testing infrastructure (CircleCI, Docker, Selenium, Locust, GCP, etc).
  • Ability to quickly learn and implement unfamiliar technologies.
  • Detail oriented within a fast-paced work environment.
  • Excellent written and verbal communication skills.
  • Analyze and tackle sophisticated software development problems spanning multiple components, sometimes outside area of expertise.
  • Be comfortable navigating large and complex codebases as well as managing Git repositories.
  • Excellent problem-solving skills with an emphasis on data-informed decision-making.

Bonus points for

  • Experience working as an SRE or DevOps Engineer would be great.
  • JavaScript and/or Rust programming language and ecosystem experience.
  • Experience with test methodologies and different test frameworks across programming languages.
  • Experience with Mercurial is appreciated.

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


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