7+ years of professional software development experience, including 2+ years in a Senior Software Engineer role
3+ years of professional mobile application development experience
Strong experience with Swift, SwiftUI, and iOS frameworks
Deep knowledge of iOS architecture, design patterns, and performance optimization
Experience delivering and maintaining complex, scalable, and reliable software
Experience addressing technical debt and refactoring large or complex codebases
Strong knowledge of mobile security, including encryption, secure storage, app signing, and vulnerability remediation
Experience with communication and email protocols such as RSS, IMAP, POP, or Matrix, and familiarity with the IETF standards for CalDav or CardDav
Advanced proficiency with Git and collaborative development workflows
Strong debugging, testing, and problem-solving skills
Strong attention to detail, curiosity, and a product-focused mindset
The ability to work independently, take ownership, and collaborate across teams
Respect for diverse skills, experiences, and perspectives
Excellent async written communication skills; comfortable working with a geographically distributed team
Ability to learn, evaluate, and responsibly use emerging technologies, including AI-enabled tools, to improve work processes
Familiarity with Apple App Store and Google Play Store compliance guidelines
Experience contributing to open-source projects or communities
Proficiency in French, German, Japanese, or another widely supported Thunderbird language
What success looks like
You’ll be successful in this role if you look beyond shipping features and improve the architecture, reliability, security, and long-term health of the product. You’re comfortable solving ambiguous problems, flagging risks early, documenting decisions, and collaborating across engineering, product, UX, users, and the open-source community
Over time, your work will help Thunderbird’s iOS experience become more resilient, scalable, and easier for both staff and community contributors to build on
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
We rely on clear communication, thoughtful documentation, and collaborative decision-making to work effectively across time zones and disciplines