Senior Full-Stack Engineer / Fractional Technical Lead – Telehealth Platform

I'm the founder of an early-stage Canadian telehealth platform currently live in production with real patients. I've led the product and development to date using modern AI-assisted development tools. The platform supports an end-to-end telehealth workflow including patient onboarding and medical assessments, clinician review, prescribing workflows, pharmacy fulfillment, payments, patient accounts, and ongoing follow-ups. As the platform moves into its next stage of growth, I'm looking for an experienced senior full-stack engineer / technical lead to independently review the existing application and help strengthen the technical foundation. The initial engagement will primarily be an architecture, security, and production-readiness review rather than immediately building new features. The core stack includes: TypeScript React / Vite Node.js / Express PostgreSQL / Supabase REST APIs and third-party integrations I'm looking for someone who can: - Review the existing codebase and architecture - Identify and prioritize meaningful technical debt, security issues, scalability concerns, and reliability risks - Review authentication, authorization, database architecture, sensitive-data handling, API design, deployment, and third-party integrations - Assess the application from the perspective of handling sensitive healthcare information - Review code produced through an AI-assisted development workflow and identify areas that should be strengthened or refactored - Help document the architecture and key data flows - Recommend practical improvements based on risk and business priority—not simply produce a long list of theoretical issues - Potentially assist with future third-party/API integrations - Potentially remain involved as a fractional technical lead as the company grows Ideal experience: - Strong TypeScript, React, Node.js and PostgreSQL experience - Production application architecture - Authentication / authorization and role-based systems - API integrations - Application security - Experience inheriting existing production applications Experience with Supabase, Stripe, healthcare/PHI, fintech, SOC 2 environments, security audits, or other regulated/sensitive-data applications is a strong plus. I'm not primarily looking for a developer to execute tickets. I'm looking for someone with strong technical judgment who can understand an existing production application, identify what actually matters, and help guide technical decisions as the platform grows. Initial engagement: approximately 10 hours reviewing the application, followed by a concise assessment of the highest-priority findings and recommended next steps. If there's a good fit, I'd be interested in continuing on a flexible/fractional basis for architecture, code review, integrations, and development. When applying, please briefly answer: - Tell me about a production application you've inherited, audited, or significantly refactored rather than built from scratch. - What's your experience with React/TypeScript/Node/PostgreSQL and Supabase? - Have you worked with healthcare, fintech, PHI/PII, or another regulated/sensitive-data application? - How would you approach your first 5–10 hours reviewing an unfamiliar production application? Please keep your response concise. I'm more interested in relevant experience and technical judgment than a long proposal.