Founding Engineer (Potential CTO)

About the Role This is a founding engineering role at an early-stage healthtech startup building an AI-powered nervous system rehabilitation platform. You'll be the second technical voice on the team — owning the full stack from a React Native mobile app to frontier AI model integration and real-time biosignal processing — and you'll help shape both the product and engineering culture from the ground up. What You'll Do Own technical direction and execution as the founding engineer, with a path to CTO. Ship the first end-to-end AI coaching experience, from the React Native app through Claude-backed inference. Architect and build an AI nervous system training coach, including model design, prompt engineering, and evaluation frameworks. Translate biosignals (HRV, breath, motion, PPG) into a real-time coaching layer tailored to each user. Build AI-powered QA and testing pipelines to support safe, high-cadence 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). What We're Looking For 3+ years in mobile and full-stack engineering with a track record of shipping 0→1 consumer mobile apps to real users. Deep fluency in React Native and ownership of the full mobile lifecycle (build, release, debug, monitor, iterate). Production experience with Claude or other frontier models, including prompt engineering, tool use, and evals. Experience with AI-native infrastructure — AI integrated across the stack, not bolted on. Backend development in Node.js or Python with PostgreSQL and modern infra (e.g. Vercel, Fly, Render). Hands-on experience with HealthKit, wearable APIs, or real-time biosignal data (HRV, PPG, motion). Founder mindset with prior first-engineer or early-stage startup experience and comfort making hard tradeoffs. Ability and willingness to work in-person in Montreal, San Francisco, or New York. Background or strong interest in nervous system science, somatics, neuroscience, or trauma research is a plus. Compensation & Benefits Salary: $170,000 USD annually. Equity: Meaningful equity offered. Visa sponsorship: Not available. Location On-site. Primary location is Montreal, Canada, with the option to work from San Francisco, CA or New York, NY.