Staff Software Engineer

The Staff Software Engineer for Web Application Services at Mozilla leads architecture decisions, guides development of web-based Thunderbird services, and drives scalable, maintainable product platforms. The role involves owning complex projects, writing and reviewing code, prototyping, evaluating technology choices, and mentoring engineers. You will collaborate with designers, product management, QA, and community contributors to shape software patterns and solutions that scale to millions of users and donors. Responsibilities include directing technical architecture for new Services products, building prototypes, developing analytics infrastructure, and ensuring sustainable, accessible systems. You will partner with cross-functional teams and stakeholders to translate product goals into robust software, and you will stay current with evolving technologies and industry practices. The position requires strong English written and verbal communication, remote collaboration across disciplines, and the ability to travel internationally when needed. What you’ll do: Lead the technical architecture of new Services products; write code, prototypes, and experiments; establish software patterns; build analytics and infrastructure; tackle high-level problems with broad impact; provide technical and product direction across Thunderbird and Mozilla; collaborate with team and community to surface issues, refine ideas, and develop practical solutions; plan improvements to make systems more accessible, self-serviceable, lower friction, scalable, and easier to delegate; mentor engineers through code review, documentation, technical discussions, process improvements, and ongoing guidance; stay current with evolving technologies, coding standards, libraries, and frameworks and apply that knowledge to your work. What you bring: 10+ years of web software development experience, expert-level JavaScript skills and knowledge of at least one additional programming language, such as Python, Rust, Go, or C++. An understanding of the business landscape, experience collaborating with teams to expand Thunderbird’s user and donor base. Experience with front-end frameworks, full-stack development, and/or API development. Strong knowledge of software development practices, including testing, code review, and documentation, and the ability to help others develop these skills. Experience acting as a technical lead, solving complex technical problems, and providing mentorship and guidance to other engineers. Experience collaborating remotely across disciplines. Excellent written and verbal English communication and documentation skills, with the ability to communicate clearly and concisely with an international, geographically distributed team. Comfort working in an open-source environment and a commitment to Mozilla values. Ability to learn, evaluate, and responsibly use emerging technologies, including AI-enabled tools, to improve work processes. A commitment to continuous learning and staying current with industry trends and technologies. Ability and willingness to travel periodically, including internationally. Bonus points for: Experience with product management or product-focused work. What success looks like: Strong technical leader who helps Thunderbird grow and evolve our product offerings; scale patterns and architecture; turn ideas into working solutions; data-driven product decisions; cross-functional direction. Work environment: This is a full-time, fully remote position. You’ll join a distributed team of Thunderbird staff, open-source community members, and contributors from around the world. Compensation & benefits: Salary ranges for US and Canada; remote-friendly benefits including paid leave, professional development stipends, hardware, and remote-work stipends.