Mozilla Corporation is the non-profit-backed technology company that has shaped the internet for the better over the last 25 years. We make pioneering brands like Firefox, the privacy-minded web browser. Now, with more than 225 million people around the world using our products each month, we’re shaping the next 25 years of technology and helping to reclaim an internet built for people, not companies. Our work focuses on diverse areas including AI, social media, security and more. The Mozilla Corporation is wholly owned by the non-profit 501(c) Mozilla Foundation. Along with thousands of volunteer contributors and collaborators all over the world, Mozillians design, build and distribute open-source software that enables people to enjoy the internet on their terms.
org (AMO) is the foundation of the Firefox add-ons ecosystem. Behind the scenes are the DevHub which enables developers to manage their extensions. To manage the ecosystem there are a series of Reviewer tools and automated moderation systems.
As a Senior Software Engineer, you’ll bring a passion for crafting resilient systems that accelerate our review and moderation teams to provide a first-class experience for Add-on developers. Deliver major features and architectural improvements across the Add-ons stack, including automated moderation pipelines, Reviewer tools, and DevHub.
Help establish and maintain engineering standards across areas such as code review, definition of done, production readiness, runbooks, incident response, on-call practices, coding conventions, and infrastructure as code.
Create robust observability systems and data-backed insights.
Provide peer feedback, share knowledge and help others grow.
Improve our CI/CD pipelines using declarative, pipeline-as-code approaches that make changes reproducible, testable, and easy to review.
Write clear technical documentation, including design notes, Architecture Decision Records, runbooks, and incident write-ups.
Collaborate with designers, product managers, QA, and community contributors to deliver end-to-end improvements.
Work within our Python/Django, MySQL, React/TypeScript, and asynchronous processing systems.
Internal developer platforms :



Create tools and paved paths that make it easier for teams to ship and operate software safely and consistently.
Contribute to team ceremonies, execute process improvement, and provide feedback on team effectiveness.
Help make production readiness, testing, recoverability, documentation, and safe deployment part of the normal development lifecycle.
Deployments, monitoring, and incident response.

Strong hands-on experience building and maintaining production applications with Python/Django.
Experience operating and improving production software systems where reliability and safe delivery matter.
Strong experience with CI/CD systems and treating pipelines and infrastructure declaratively as code.
Experience designing or improving automated testing and deployment workflows, including integration testing and staged or progressive delivery.
Experience building or maintaining internal tools or platforms used by other engineering teams, with an understanding that internal systems have users, reliability expectations, roadmaps, and lifecycle considerations.
Ability to read and understand unfamiliar codebases and trace application behavior across frontend, backend, asynchronous jobs, data stores, and infrastructure.
Strong technical writing skills, with experience creating useful documentation such as design documents, ADRs, runbooks, and incident reports.
Experience working iteratively with a visible backlog, regular stakeholder feedback, and retrospectives that result in concrete improvements.
Bonus points for:
Experience with infrastructure-as-code tooling and policy-as-code.
Experience with chaos engineering, disaster recovery testing, or production readiness reviews.
Contributions to open source projects




Generous performance-based bonus plans to all eligible employees - we share in our success as one team
Rich medical, dental, and vision coverage
Generous retirement contributions with 100% immediate vesting (regardless of whether you contribute)
Country specific holidays plus a day off for your birthday
One-time home office stipend
Considerable paid parental leave
Employee referral bonus program
Other perks (life/AD&D;, disability, EAP, etc. - 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. 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 orientation s, 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. 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.

LI-REMOTE

104,000—$139,000 CAD

94,000—$126,000 CAD

📌 Senior Software Engineer, asap, Remote (Canada)
🏢 Mozilla
📍 Canada