Shopify B2B Integration Developer

We are looking for an experienced Shopify developer to build a B2B integration between Shopify and our existing medical inventory ERP. The ERP is built with React, TypeScript, Firebase Firestore, Firebase Storage, and a backend API layer. It contains customer companies, contacts, billing and shipping locations, customer-specific pricing, products, warehouses, inventory, orders, and approval workflows. # Scope - Build a Shopify app using the Admin GraphQL API - Synchronize ERP companies, contacts, and locations with Shopify B2B - Synchronize products, variants, SKUs, images, and metadata - Synchronize sellable inventory by Shopify location - Support ERP-controlled customer-specific pricing - Integrate customer approval and licensing status - Receive Shopify orders through webhooks and send them to the ERP - Implement retries, idempotency, logging, and reconciliation - Add customer-account or checkout extensions where appropriate - Provide technical documentation and deployment instructions # Required Experience - Shopify B2B company, contact, and location APIs - Shopify Admin GraphQL API, OAuth, and webhooks - Shopify app and customer-account extension development - Product, catalog, price-list, and inventory synchronization - TypeScript and Node.js - Firebase or comparable backend systems - Secure API and webhook design # Important Architecture Requirement The ERP must remain the source of truth for pricing, inventory, approval, licensing, and customer records. The solution must not expose privileged Firestore access directly to the storefront. # Proposal Requirements Please include: - Examples of Shopify B2B integrations you have built - Your recommended architecture for this project - Estimated timeline, availability, and hourly or fixed-price expectations