Fractional CTO / Founding Engineer — GI Health Symptom Tracking Platform

About the project We're building a patient-facing IBS symptom tracking app with a connected physician portal — patients log symptoms, food, bowel movements, and medications; physicians get a real-time view of their patients' data, secure messaging, and AI-generated pre-visit summaries. The long-term goal includes qualifying physicians for reimbursement under CMS billing programs (Chronic Care Management, and potentially Remote Therapeutic/Physiologic Monitoring), which makes HIPAA compliance and data architecture foundational, not an afterthought. We have a working technical foundation already in place: a full relational data model, an initial FastAPI backend with JWT auth and role-based access control, a sprint-by-sprint build plan through MVP and billing integration, and high-fidelity mobile app mockups. What we need is an experienced technical lead to take ownership of the architecture, make the calls we can't make ourselves, and guide (or directly do) the build from here. What you'd own Architecture and technical decision-making — validate, challenge, or revise our existing schema and API design; make the calls on infrastructure, hosting, and vendor selection HIPAA compliance posture — BAAs with cloud and AI vendors, encryption and access-control implementation, audit logging design, risk assessment Engineering execution or oversight — either build directly (FastAPI + PostgreSQL backend, React Native/Expo patient app, React physician portal) or manage contractors doing so, depending on engagement scope Vendor evaluation for device/wearable integration (RPM), auth (Auth0/Cognito), and infrastructure (AWS/GCP) Technical roadmap ownership as the product moves from MVP through the billing-integration phases What we're looking for Required Prior experience shipping a product that handled PHI or other regulated personal data under HIPAA (or a comparably strict framework — GDPR healthcare data, financial PII, etc.) Full-stack comfort — able to speak credibly to both backend/infra (Python or Node, PostgreSQL, cloud hosting) and mobile (React Native or equivalent) Can explain, concretely, how they've handled a BAA review, a HIPAA risk assessment, or an audit-logging implementation — not just familiarity with the acronym Comfortable in a fractional/advisory capacity — this is not a 9-to-5 employee relationship, at least initially Strongly preferred Prior digital health or health-tech startup experience Familiarity with FHIR or EHR interoperability Experience with CMS billing program requirements (RPM/RTM/CCM) or willingness to learn this domain quickly Experience integrating wearable/IoT health devices (pulse oximetry, HR monitors) via vendor APIs