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.