Founding Full-Stack iOS Engineer

About the Role

This is a founding engineering opportunity at a Y Combinator–backed consumer wearable startup operating at the intersection of biometrics, emotional intelligence, and mobile software. The company is building a wearable device that reads emotional states in real time — think of it as a fitness tracker, but for your EQ — powered by a proprietary computational neuroscience inference model processing over 150 audio and biometric signals.

As the Founding Full-Stack iOS Engineer, you will own the companion iOS app end-to-end. This is a high-ownership, high-impact role: you'll be one of the first engineers at the company, expected to grow into a leadership position as the team scales. Prototypes are already on users' wrists — this is a real product with real momentum.

What You'll Do

• Own the companion iOS app end-to-end, from architecture decisions to pixel-perfect UI delivery

• Surface emotional-state outputs (energy, mood, focus scores) from the backend inference model in a clear, compelling, and polished consumer experience

• Collaborate closely with the founding team — including hardware, neuroscience, and design — to shape the full product experience

• Build and maintain full-stack integrations between the iOS app and backend services

• Set engineering standards and best practices as the mobile org grows around you

What We're Looking For

Required

• Several years of professional experience shipping consumer-grade iOS apps (no fresh graduates)

• Strong proficiency in Swift and the iOS ecosystem

• Full-stack capability — comfortable working across mobile and backend layers

• Track record of owning and delivering polished, production-quality mobile products

• Self-directed and comfortable working in a fast-moving, early-stage environment

Nice to Have

• Experience with health, fitness, or wearable consumer apps

• Familiarity with biometric data, Bluetooth/BLE hardware integration, or real-time data streaming

• Prior founding or very early-stage startup experience

Compensation & Benefits

• Salary: ~$150,000 USD (or ~£75,000 GBP for London-based candidates)

• Equity: Up to 1–2% — meaningful founding-level ownership

• Early-stage company with Series A/B angel and strategic-partner funding round in progress

• Visa sponsorship: Not available for new sponsorships; visa transfers are welcome

Location

Primary office in London, United Kingdom. The team is also present in San Francisco. Flexible arrangements considered for the right candidate — on-site or remote.