Founding Engineer (Potential CTO)

### About the Role This is a rare **Founding Engineer (potential CTO)** opportunity at a seed-stage, AI-native digital health startup focused on nervous system repair and chronic disease management. You'll be the second technical voice at the company — the person who turns a bold product vision into a production-quality AI mobile experience, and who defines the engineering culture and stack for the next decade. You'll own the full technical journey: from shipping the first end-to-end AI coaching experience in a React Native app, to architecting the model and feedback loop that powers a real-time nervous system training coach using wearable biosignal data. This role is **in-person** in Montreal, San Francisco, or New York City, and is central to everything the founding team builds. ### What You'll Do - Serve as Founding Engineer and potential CTO, owning technical direction and day-to-day execution. - Ship the AI coaching product v1 end-to-end — from a React Native mobile app to Claude-backed inference and wearable integrations. - Architect and build an AI-powered nervous system training coach, including model design, prompt engineering, tool use, and evaluation pipelines. - Translate biosignals (HRV, breath, motion, PPG) into a real-time personalized coaching layer. - Build and maintain AI-powered QA and testing pipelines to enable safe, fast daily shipping. - Own full-stack decisions across frontend, backend, infrastructure, and AI-native layers. - Integrate iOS/HealthKit and wearable platforms (e.g. Apple Watch, Oura, Whoop, EEG headbands). - Collaborate closely with the founding team on-site in Montreal, SF, or NYC. ### What We're Looking For **Dealbreakers (must-haves):** - Production experience shipping and operating Claude or other frontier LLM-based systems, including prompts, tool use, and evals. - Willingness and ability to work in-person in Montreal, San Francisco, or New York City. - 3+ years in mobile/full-stack engineering with a track record of delivering 0→1 consumer mobile apps to real users. **Required skills & experience:** - Deep fluency in **React Native** with end-to-end ownership of the mobile lifecycle (build, release, debug, monitor, iterate). - Experience with AI-native infrastructure where AI functions are integrated across all layers — not bolted on. - Backend development in **Node.js or Python** with **PostgreSQL** and modern infra (Vercel, Fly, Render, or similar). - Ability to move fluidly across the full stack (frontend, backend, infra, AI) with minimal handholding. - Hands-on experience with **HealthKit, wearable APIs, or real-time biosignal data** (HRV, PPG, motion). - Founder mindset: comfortable making hard tradeoffs, operating with high autonomy, and building from zero. **Nice to have:** - Experience building AI-powered testing or evaluation pipelines. - App Store shipping experience — a consumer mobile app with real, active users. - Background or genuine interest in nervous system science, somatics, neuroscience, or trauma research. - Prior experience as the first or founding engineer at an early-stage startup. ### Compensation & Benefits - **Base salary:** $170,000 USD / year - Early-stage equity commensurate with founding-team scope - High-impact, high-ownership role with a direct path to CTO *Visa sponsorship is not available for this role.* ### Location This is a fully **on-site** role. The founding team works together in person across **New York City, San Francisco, or Montreal**. Candidates must be able to commit to in-person collaboration at one of these locations.