Staff Product Engineer, Enterprise AI - Mozilla

Why Thunderbird?

Thunderbird is one of the world’s most trusted open-source email applications, empowering more than 20 million people globally. At MZLA, the team behind Thunderbird, we build privacy-respecting communication and productivity tools that help people manage their digital lives while staying in control of their data.

We are open source by design. Our products are developed transparently and in collaboration with a global community of contributors, and that same spirit shapes how we work: collaboratively, inclusively, and with a shared commitment to putting users first.

We are a small but growing company of 60+ people distributed across seven countries. As Thunderbird evolves beyond a single desktop application, we are expanding across desktop, mobile, paid services, and new product experiences that help people and organizations work more effectively without giving up control to big tech ecosystems.

The Opportunity

Thunderbolt is an open-source, cross-platform AI product initiative from the team behind Thunderbird. It is built around a clear principle: people and organizations should be able to use AI while staying in control of their data, infrastructure, model choices, and long-term options.

We’re looking for a Staff Product Engineer to help build Thunderbolt as it moves from early product development into enterprise use cases. This role sits at the intersection of full-stack product engineering, AI-enabled product development, enterprise workflows, technical execution, product judgment, and post-launch iteration.

What You’ll Do

• Own the implementation of Thunderbolt product features from concept through launch, adoption, and iteration.
• Translate product vision, user needs, partner feedback, and enterprise requirements into practical technical plans and shipped product experiences.
• Work across the stack to build, integrate, test, and ship complete product features for AI-powered chat, search, research, workflow automation, administration, integrations, and enterprise workflows.
• Partner closely with product, design, engineering, enterprise-facing teams, and open-source contributors to clarify requirements and deliver high-quality outcomes.
• Use AI-assisted development tools thoughtfully to accelerate implementation while maintaining strong judgment around quality, security, maintainability, and reliability.
• Write clear, maintainable, well-tested code across front-end, back-end, APIs, integrations, and infrastructure-adjacent areas.
• Help establish reusable product and engineering patterns that allow future features to be built more efficiently.

What You Bring

• 10+ years of professional software engineering experience, including significant experience building and shipping production applications with Staff-level scope, leadership, and impact.
• Strong full-stack engineering skills across user interfaces, APIs, services, integrations, data flows, and infrastructure-adjacent areas.
• Experience building AI-enabled products or features, with practical familiarity in LLMs, RAG, agents, model/provider abstraction, data connectors, retrieval systems, or AI application architecture.
• Experience working with open-source enterprise products, developer tools, infrastructure products, platform products, or complex enterprise software.
• Strong product judgment and comfort operating independently in a fast-changing product environment.
• Awareness of enterprise software needs, including privacy, security, administration, access control, compliance, and deployment flexibility.

Work Environment & Benefits

This is a remote position open to applicants who reside in and have permanent work authorization for the United States or Canada. We offer fully remote work flexibility, competitive compensation, annual bonuses, remote work and wellbeing stipends, professional development support, comprehensive health/dental/vision plans, retirement contributions, and generous paid time off.