Shopify App Developer (Expert) — Python + Shopify Auth Integration

Project Overview We’re looking for an experienced Shopify App Developer with strong expertise in Python to refine and complete an authentication flow between our Shopify app and an external backend service. This role requires a deep understanding of Shopify app frameworks, OAuth, secure token exchange, session handling, and backend integration. Our app is already built, but we need an expert to finalize and stabilize the authentication layer so that: Shopify stores can securely install and authenticate with our app The app can authenticate with our external backend service (Python-based API) Sessions, tokens, and handshakes are handled cleanly and consistently across the entire flow If you’ve built Shopify apps that communicate with external services before—this will be very familiar territory. Responsibilities Audit the current authentication flow between the Shopify app and the external Python backend Fix and/or rebuild the required authentication endpoints Implement secure OAuth flows for Shopify (including online/offline tokens) Ensure proper token persistence (Shopify tokens + backend service tokens) Validate HMAC signatures, webhooks, and session details Help us establish best practices for long-term stability and scalability Collaborate with our internal developer to integrate improvements cleanly Required Skills & Experience 5+ years building production Shopify apps Expertise with Shopify OAuth, session storage, and the full authentication lifecycle Comfortable with Python (FastAPI, Django, or Flask) for backend API work Solid understanding of HMAC validation, webhooks, and secure request signing Experience integrating Shopify apps with external APIs/services Ability to read and debug someone else’s code quickly Strong communication and documentation skills Apply tot his job