Thunderbird Full Stack Developer

at Mozilla Foundation
Remote Canada, Remote US

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 role is an opportunity for an experienced engineer who is excited to design and implement Thunderbird’s ongoing growth.

The Opportunity

We’re looking for a Full-Stack Developer, who will play a pivotal role on a new product line. You will shape and build a new product from early prototyping, to MVPs, to finding product market fit.  You are inventive, creative, and know just how far to plan ahead for a project that operates more like a startup than an established software product. You will work with a small cross-functional team that includes design and product management, and you will have wide latitude to operate independently with your teammates. You love to be invigorated by new challenges, you love working collaboratively, and you will have a team that supports you in making your very best contribution. We’re committed to creating an amazing experience for our users, and you’ll play a key part in this effort. You will be working with our existing staff and community members from all over the globe. We are key contributors to open source, allowing you to show your skills to the world both in terms of pure code and concrete product improvements. This is a remote, full time position. We expect excellent written communication skills so as to foster strong work coordination over email, video conferencing, Matrix, and Bugzilla.

What you’ll get to do:

  • Write code and tests, build prototypes, tackle problems with no clear solution, and collaborate with other designers and engineers as part of a global, distributed open source development team. This will involve technical decision making, code reviews (receiving and giving), engagement with contributors, planning and other collaborative development practices.
  • Help to build a comprehensive, threaded rework of the Thunderbird Calendar back-end from data storage to communication with calendar providers.
  • Debug and fix problems to improve the quality of our complex code base, making a better experience for tens of millions of users.
  • Since we’re a small team, you’ll have a major impact on the design and development of Thunderbird code and take ownership of the projects you work on.

We’re looking for someone with:

  • 3+ years of full-stack software development experience.
  • Proficiency with Javascript and/or Python, client- and server-side (Node.js, FastAPI).
  • Familiarity with a front-end frameworks including Svelte, Vue or React.
  • Experienced with SQL-based databases and NoSQL document stores.
  • Adept with Google Cloud Platform or Amazon Web Services.
  • Experience developing software products in a startup or highly lean environments.
  • Experience with application security fundamentals and best practices.
  • Great communication skills (both written and verbal), documentation skills, and the ability to work with a multi-disciplinary, geographically distributed team.
  • Comfortable working on all levels of a complex software stack, as well as strong learning and exploration skills..
  • Deep respect for the different skills and perspectives that people of varied technical and non-technical backgrounds bring to a team.
  • Dedication to open source and open standards.
  • Proven ability to deliver and maintain complex software projects
  • A passion for protecting users.

Bonus Points for:

  • Past experience developing web browser add-ons.
  • French, German, Japanese, or any language proficiency in addition to English.

Hiring Locations:

  • North America (Canada, US) - Remote

We offer the following benefits:

  • 24 paid time off days per year (prorated) + your birthday
  • Company/public holidays + year-end shutdown
  • Health, Dental, and Vision Insurance
  • Life Insurance + Accidental Death & Dismemberment
  • Short-Term Disability and Long-Term Disability
  • Employee Assistance Program (EAP)
  • Retirement Plan contributions
  • Remote Work Set-Up: latest hardware + internet reimbursement
  • Maternity and Parental leaves

Benefits are subject to change at any time at the discretion of MZLA Technologies Corp.

Applicants must reside in and have existing work authorization for the country location specified. We are unable to consider applicants outside of these locations and are unable to provide visa sponsorship.

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

Group: C


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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
  • 5 global offices: San Francisco, Toronto, Paris, 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