Founding Engineer (Potential CTO)

This position is listed on behalf of a partner company, who manages all applications and next steps. Our partner is looking for a Founding Engineer (Potential CTO) based in Canada. This is a high-impact founding engineering opportunity at an early-stage healthtech startup developing an AI-powered nervous system rehabilitation platform. You will be the second technical leader, taking ownership of the product and technology stack from mobile experience to AI infrastructure and real-time biosignal processing. The role offers significant influence over architecture, product direction, engineering practices, and the future technical organization. You will build an AI coaching experience that combines frontier AI models with personalized physiological data and wearable technologies. Working closely with the founding team, you will turn ambitious concepts into reliable products used by real customers. The position is ideal for a hands-on engineer who thrives in ambiguity, moves quickly, and is comfortable making foundational technical decisions. There is a clear path toward a CTO role for someone who demonstrates strong technical leadership and a compelling founder mindset. Own technical direction, architecture, and execution as the founding engineer, with the potential to grow into the CTO role. Build and launch the first end-to-end AI coaching experience, spanning the React Native mobile application through AI model inference. Architect and develop an AI-powered nervous system training coach, including model integration, prompt engineering, tool use, and evaluation frameworks. Translate real-time biosignals such as HRV, breathing, motion, and PPG into personalized coaching experiences for users. Develop AI-powered quality assurance and testing pipelines that enable safe, reliable, and high-frequency product releases. Make full-stack technical decisions across mobile frontend, backend services, infrastructure, databases, AI-native systems, and integrations. Build and maintain integrations with iOS HealthKit and wearable platforms such as Apple Watch, Oura, Whoop, and EEG headbands. Own the complete mobile product lifecycle, including development, release management, debugging, monitoring, iteration, and ongoing optimization. Work closely with the founding team to translate product vision into scalable technical solutions and prioritize high-impact initiatives. Establish engineering practices, technical standards, and development processes that can support the growth of the future engineering organization. Make pragmatic architectural and product trade-offs in a fast-moving environment while maintaining quality, reliability, and user safety. Requirements: 3+ years of experience in mobile and full-stack software engineering, with a demonstrated ability to take consumer mobile products from 0→1 and ship them to real users. Deep proficiency with React Native and experience owning the complete mobile development lifecycle. Production experience with Claude or other frontier AI models , including prompt engineering, tool use, model integration, and evaluation. Strong understanding of AI-native application architecture, with experience integrating AI throughout the product and technology stack rather than treating it as an isolated feature. Backend development experience using Node.js or Python , ideally with PostgreSQL and modern cloud infrastructure such as Vercel, Fly, or Render. Hands-on experience with Apple HealthKit, wearable APIs, or real-time biosignal data , including HRV, PPG, motion, or related physiological signals. Strong architectural and systems-design capabilities, with the ability to make independent technical decisions in an early-stage environment. Founder mindset, entrepreneurial approach, and ideally previous experience as a first engineer or early-stage startup team member. Ability to operate effectively with significant autonomy, ambiguity, changing priorities, and limited resources. Strong communication and collabo