Staff Mobile Engineer, iOS

at MZLA/Thunderbird Locations: Remote US, Remote Canada

Why Thunderbird?

• MZLA Technologies Corporation (MZLA) is a wholly owned, for-profit subsidiary of the Mozilla Foundation and home to Thunderbird, an open-source email and productivity platform used by over 20 million people globally.
• MZLA operates independently from Mozilla Foundation and Mozilla Corporation.
• All products are open source, developed transparently with a global community.
• The team has 50+ people across seven countries.
• Thunderbird is evolving into a suite of privacy-respecting productivity tools independent of big tech ecosystems.
• Revenue model combines community donations and subscriptions for cloud-based services.

The Opportunity:

• Senior individual contributor role with deep iOS expertise.
• Design, develop, and evolve Thunderbird’s iOS application.
• Work on complex technical problems and lead significant mobile initiatives.
• Collaborate on architectural decisions with senior engineers and leadership.
• Deliver high-quality iOS experiences focusing on performance, reliability, accessibility, security, and maintainability.
• Influence, mentor, and guide other engineers.
• Full-time remote position across multiple regions/time zones.

What you’ll do:

• Tackle complex mobile development challenges requiring thoughtful design and coordination.
• Serve as technical lead on major iOS initiatives including feature development and architectural improvements.
• Collaborate on mobile technical direction and architecture decisions.
• Improve code quality by reducing technical debt and enhancing performance, stability, and build health.
• Partner with product and UX teams to ensure usability and accessibility in iOS implementations.
• Write high-quality, testable, maintainable iOS code for a consistent codebase.
• Mentor other engineers via code reviews, guidance, knowledge sharing.
• Improve engineering practices/workflows; stay current with iOS technologies.

What you’ll bring:

• 10+ years professional software development experience; senior-level complex mobile app experience required.
• Deep experience with Swift and iOS frameworks.
• Expertise in mobile architectures,...