Senior Engineering Manager (AI Product, Thunderbolt)

• 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 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
• Thunderbolt is an open-source, cross-platform AI product initiative from the team behind Thunderbird. It is being 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. Thunderbolt is designed to support flexible deployment models, integrations with AI tools and workflows, and use cases across desktop, web, and mobile
• We are looking for a Senior Engineering Manager to lead engineering execution, people management, and operating practices for Thunderbolt as it moves from R&D incubation into a more mature product and enterprise development phase
• This role will help the team define what production-ready means at this stage: stronger release discipline, clearer ownership, higher user-facing product quality, stronger engineering practices, and a more scalable operating model
• This is a hands-on technical management role. The Senior Engineering Manager will manage a senior engineering team, stay closely engaged with the codebase and technical execution, coordinate work across employees, contractors, and technical partners, and help the team deliver a reliable, enterprise-ready open-source AI product
• The right person will bring strong people management skills, strong product engineering judgment, and enough technical depth to evaluate engineering work credibly, support architectural and implementation tradeoffs, and help the team keep shipping with quality
• Lead engineering execution by clarifying priorities, ownership, timelines, risks, dependencies, and quality expectations
• Manage engineers and contractors, including coaching, feedback, prioritization, performance support, and team development
• Stay close to the codebase by contributing code, reviewing technical work, evaluating tradeoffs, and helping the team maintain momentum and quality
• Partner with technical and product leadership to turn product direction, AI strategy, user experience goals, and technical priorities into coordinated engineering plans
• Establish planning, review, release, and follow-through practices that improve predictability and reduce bottlenecks
• Maintain high standards for code quality, testing, documentation, reliability, security awareness, maintainability, and release readiness
• Build strong product and architectural context across AI-enabled workflows, integrations, local-first or customer-controlled architectures, and release requirements
• Partner across product, design, enterprise-facing teams, and technical leadership to balance speed, user experience, privacy, quality, enterprise readiness, and long-term sustainability
• Lead hiring, onboarding, and resource planning as the Thunderbolt engineering team grows
• Help Thunderbolt scale from an incubation-stage product into a reliable, enterprise-ready open-source AI product
• This is a full-time, fully remote position. You’ll work with our passionate staff, open-source community members and partners from all over the globe

Benefits

• Health and wellness: Mozilla covers medical, dental and vision plan premiums at 100% for U.S. and Canadian employees. Our offerings give you the options you need to manage your health — and your family’s — the way you want.
• Mental health: Mental health is as important as our physical health. That’s why Mozilla’s health benefits include therapy and coaching sessions to make sure our people have access to the care they need.
• Time away: With all of life’s demands, time away from work to disconnect and recharge is essential. In addition to country-specific holidays (12 in the U.S. and Canada), vacation and sick time start accruing right away (specifics vary by country). Everyone also takes a pause together on quarterly all-company wellness days, plus you get to celebrate the…