Founding Full-Stack iOS Engineer

About the Role This is a founding engineering role at a Y Combinator–backed wearable AI startup, where you'll own the companion iOS app end-to-end — translating real-time emotional-state inferences into intuitive, consumer-grade experiences. You'll be an early team member with meaningful product ownership, sitting at the intersection of cutting-edge AI and polished mobile design. What You'll Do Own the iOS app from architecture through deployment, iteration, and ongoing maintenance. Surface emotional-state outputs from a proprietary AI inference model through clean, accessible mobile interfaces. Build and ship a high-quality consumer mobile experience that meets demanding product standards. Integrate backend APIs — including authentication, data sync, and data models — to support the full mobile stack. Make autonomous technical decisions as a founding engineer, helping to shape the long-term platform architecture. What We're Looking For 3+ years of professional iOS development experience with Swift and a proven track record of shipping production-ready consumer iOS apps. Strong full-stack capabilities spanning mobile development and backend API integration. Experience integrating machine learning model outputs or inferences into a mobile UX. Demonstrated end-to-end ownership of mobile features, from concept through release and ongoing iteration. Proficiency delivering polished, performant consumer UI/UX with smooth user experience. Strong CS fundamentals and comfort making independent technical decisions. Ability to collaborate effectively across time zones on a distributed team. Work authorization in the UK or US required; new visa sponsorship is not available (H-1B transfers considered). Compensation & Benefits Base salary of $150,000 USD (or approximately £75,000 GBP for London-based candidates), plus up to 1–2% equity . No new visa sponsorship; H-1B transfers may be considered. Location Flexible — remote or on-site. Primary office location is London, UK , with a presence also in San Francisco, CA. Candidates must be comfortable working across time zones.