Senior iOS Engineer

<h4><strong>Why Thunderbird?</strong></h4> <p><span>MZLA Technologies Corporation (MZLA) is a wholly-owned, for-profit subsidiary of the Mozilla Foundation and the home of Thunderbird. Thunderbird is a global, free, and open-source email and productivity app, which has experienced significant growth in revenue, staff, and aspirations since its launch 20 years ago. Our revenue comes from our dedicated users around the world who generously fund our work. As we continue to expand our team and enhance our products and services, we remain dedicated to providing best-in-class productivity solutions independent of big tech. Operating as a small but dynamic team of 40 + staff across seven countries and time zones, we are part of the larger Mozilla family but maintain our distinct and independent identity from both the Mozilla Foundation and Mozilla Corporation.</span></p> <p><span>Our organizational culture is driven by our mission. We are committed to </span><strong>fostering openness</strong><span> and </span><strong>transparency</strong><span> as a member of the open-source community. We lean into </span><strong>collaboration, creativity, and diversity</strong><span>. We bring a hearty dose of </span><strong>scrappy grit </strong><span>and </span><strong>resilience</strong><span> to our lively and spirited team. Our operating principles leverage </span><strong>data informed decisions</strong><span>, </span><strong>ownership</strong><span>, </span><strong>speed</strong><span> and </span><strong>efficiencies</strong><span> to elevate our work and deliver innovative and impactful solutions to our users.</span></p> <h4><strong>The Opportunity:</strong></h4> <p><span>As a Senior Software Engineer for iOS at MZLA, you will play a key role in shaping Thunderbird’s mobile platform. After a successful launch of Thunderbird for Android, we’re looking to expand our product portfolio to provide a mobile experience on iOS. This position offers the opportunity to build an open-source mobile product from the ground up—we are starting from a blank slate.</span></p> <p><span>The ideal candidate is a seasoned engineer who will have deep expertise in mobile application development foriOS, with experience using languages and frameworks such as Swift and SwiftUI, as well as a proven ability to optimize application performance and design scalable mobile architectures within open-source environments. </span></p> <p><span>This role will lead the development of Thunderbird’s mobile applications for iOS, shaping their technical direction and ensuring exceptional performance. This role focuses on evolving the mobile platform to meet the needs of Thunderbird’s global user base.</span></p> <p><span>We’re committed to creating an amazing experience for our users, and you’ll play a key part in this effort. As part of the MZLA Mobile team you will be working with our existing staff and community members from all over the globe to support the mission and objectives of MZLA Technologies Corp and the Thunderbird Project. Additionally, you’ll have the opportunity to engage with other mobile engineers across the broader Mozilla ecosystem. </span></p> <p><span>The Sr Software Engineer, iOS is an individual contributor and will report directly to the Senior Manager, Mobile Engineering. </span></p> <p><span>This is a </span><strong>remote</strong><span>,</span><strong> full time </strong><span>position. We require strong written communication skills to facilitate effective work coordination across various virtual communication platforms such as email and video conferencing.</span></p> <h4><strong>What you’ll do: </strong></h4> <ul> <li><span>Build and refine Thunderbird’s mobile products and platform architecture, ensuring scalability, performance, reliability, and user-centered design.</span></li> <li><span>Develop a deep understanding of the codebase and architecture to confidently make changes across the entire stack.</span></li> <li><span>Develop and maintain strong debugging and testing practices, utilizing unit, integration, and automated testing frameworks to ensure software quality and reliability.</span></li> <li><span>Conduct thorough code reviews and provide guidance on architectural improvements, test integration and development best practices.</span></li> <li><span>Independently resolve technical challenges, including performance bottlenecks, security vulnerabilities and cross-platform integration.</span></li> <li><span>Monitor application vitals and identify potential issues before they escalate.</span></li> <li><span>Document technical decisions, systems architecture, and team processes to ensure transparency, maintainability, and knowledge transfer.</span></li> <li><span>Own assigned projects, collaborating cross-functionally to investigate, plan, develop, validate, and deliver within established project timelines.</span></li> <li><span>Work directly with users and contributors to gather information to reliably reproduce bugs and then