Thunderbird Build & Release Engineer
at Mozilla Foundation

The Company

MZLA Technologies Corporation (MZLA) is a new, wholly owned subsidiary of Mozilla Foundation which runs the Thunderbird project. Thunderbird is a global, free, and open source email client that has grown significantly since its launch 10+ years ago! The project is governed by its community, which means that strategic and other high-level decisions are publicly discussed and decided upon by the elected Thunderbird Council. Thunderbird has grown in donations, staff, and aspirations over the last years. It is looking to mature and expand its business practices to ensure future operational success. This new role is an opportunity for an experienced engineer who is excited to design and implement automation to support Thunderbird’s ongoing growth.

The Opportunity

Thunderbird is looking for a multi-skilled self-starter to work on release engineering. You will be working in close cooperation with our current release engineer, reporting to our infra team lead and other staff, as well as with community members.

This is a remote, full time position. You are expected to have excellent written communication skills and coordinate your work over email, video conferencing, Matrix, and Bugzilla.

As a release engineer you will be serving the community, empowering them to make their contributions available to millions of people worldwide.

What you’ll get to do:

  • Work with a geographically-distributed development team.
  • Improve and maintain the continuous integration systems that developers rely on to accelerate productivity.
  • Develop the build and release systems used to make final builds available to users.
  • Collaborate with QA, security, localization, and engineering to ship beta and release builds.
  • Adapt changes made by the Firefox engineering teams for Thunderbird.

We’re looking for someone with:

  • Solid scripting knowledge (shell, Python).
  • Dedication to open source and open standards.
  • Ability to debug build and compile issues.
  • Familiarity with using distributed version control systems (primarily Mercurial and Git).
  • Proven track record of finishing projects.
  • Devops knowledge for cloud based setups (AWS, Linode etc.)
  • A mission of making a concrete positive impact on the day to day communication experience for tens of millions of users.

Bonus points for:

  • A working knowledge of C/C++, Rust, and/or Javascript.
  • Experience with Taskcluster.
  • Low level system experience on Linux, Windows, and/or Mac.
  • Experience with legacy build systems such as make, or modern ones such as Bazel, Buck or Blaze.
  • Previous open source engagement.

MZLA Technologies Corporation (MZLA) Hiring Practices

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, and persons of all sexual orientations and gender identities and expressions.

We are an equal opportunity employer and value diversity. We do not discriminate on the basis of race, religion, color, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status.

We will ensure that individuals with disabilities are provided reasonable accommodation to participate in the job application or interview process, to perform essential job functions, and to receive other benefits and privileges of employment. Please contact us to request accommodation at

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