Founding Engineer (Potential CTO)

About the Role

A well-funded, early-stage healthtech startup is looking for a Founding Engineer (with CTO potential) to be the second technical voice at the company. This is a rare opportunity to own the full technical direction of a clinically grounded AI mobile product that uses biofeedback and biosignal data to help people repair their autonomic nervous system and manage chronic symptoms.

You'll ship the first end-to-end AI coaching experience, design the underlying model and feedback loop, define the engineering culture, and make foundational stack decisions that will shape how the company builds for years to come. This role is on-site in Montreal, San Francisco, or New York City — candidates must be willing and able to work in person.

Visa sponsorship is not available for this role.

What You'll Do

• Serve as the Founding Engineer and potential CTO, owning technical direction and hands-on execution.

• Ship the first AI coaching experience end-to-end — from the React Native mobile app to frontier-model-backed inference and wearable integrations.

• Architect and build the AI nervous system training coach, including model design, prompt engineering, tool use, and evaluation frameworks.

• 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, continuous 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 in person to move fast and make hard tradeoffs.

What We're Looking For

Dealbreakers (must-haves):

• Proven, hands-on experience shipping and operating Claude or other frontier models in production — including prompts, tool use, and evals.

• Willingness and ability to work on-site in Montreal, San Francisco, or New York City.

• 3+ years of mobile/full-stack engineering experience, with at least one 0→1 consumer mobile app shipped and operated with real users.

Required:

• Experience with AI-native infrastructure where AI capabilities are integrated across layers (not bolted on).

• Backend development in Node.js or Python with PostgreSQL and modern infra (e.g., Vercel, Fly, Render).

• Ability to move fluidly across the stack — frontend, backend, infra, and AI — with minimal handholding.

• Deep fluency in React Native and full ownership of the mobile lifecycle (build, release, debug, monitor, iterate).

• Experience with HealthKit, wearable APIs, or real-time biosignal data (HRV, PPG, motion).

Nice to Have:

• Experience building AI-powered testing or evaluation pipelines.

• Prior experience as the first or only engineer at a startup.

• Background or strong interest in nervous system science, somatics, neuroscience, or trauma research.

Compensation & Benefits

• Base salary: $170,000 USD

• Equity: Meaningful equity package offered (ranging up to significant founder-level upside based on performance and trajectory)

• Direct path to CTO for the right candidate

Location

This is an on-site role. The primary location is Montreal, Canada, with the option to be based in San Francisco, CA or New York, NY. Regular in-person collaboration with the founding team is expected. Visa sponsorship is not available.