I help Shopify teams trace one broken app, webhook, Billing API, or Admin API path and turn it into a clear fix plan or narrow working patch. Best fit: - OAuth/install or app-review blockers - webhook retries, duplicate events, HMAC checks, or missing logs - Admin API jobs that need idempotency and handoff notes - a small audit before committing to a larger build Deliverable: - failing-path map - reproduction notes - prioritized fix list - one narrow patch or implementation plan when access and scope are clear - concise handoff notes so the result is not a black box Public proof: PackBridge and Script Sentinel show the same reliability lane: Shopify app backends, webhooks, signed payloads, audit reports, and deployment/app-review discipline. I use Claude and Copilot for parts of my workflow. All code and deliverables go through me before they reach you.