Seeking Developers for Warehouse Management System

We're looking for an experienced software development agency (or an established full-stack team) to build a modern, cloud-native Warehouse Management System (WMS) from the ground up. This is not a simple inventory application. The product is intended to become a commercial SaaS platform capable of serving warehouse operators, third-party logistics (3PL) providers, and e-commerce brands with deep Shopify integration and enterprise-level warehouse functionality. A comprehensive 23-page Product Specification Document has already been completed and will be shared with shortlisted candidates. Project Overview The platform includes: Full Warehouse Management System Shopify integration Bin/location management Receiving (ASN / Purchase Orders) Pick / Pack / Ship workflows Inventory management Returns (RMA) Labor management Warehouse mapping Analytics dashboards Multi-client (3PL) support Customer portal Billing engine Shipping integrations Mobile warehouse application Multi-warehouse architecture Preferred Technology Stack Frontend Next.js React Tailwind CSS Backend Node.js (Fastify preferred) or Python FastAPI Database PostgreSQL Caching / Queues Redis Mobile React Native Infrastructure AWS or Railway Docker GitHub Actions CI/CD Integrations Shopify (REST + GraphQL) EasyPost or ShipStation QuickBooks Online UPS / FedEx / USPS What We're Looking For We're specifically looking for a development team that has experience building products such as: Warehouse Management Systems (WMS) ERP platforms Supply Chain software Logistics software Inventory Management Systems Order Fulfillment Platforms SaaS products Shopify applications Enterprise dashboards Experience with warehouse operations is a major advantage. Required Experience Please apply only if your team has experience with several of the following: Shopify API Inventory systems Warehouse software Barcode workflows REST APIs PostgreSQL Redis React Next.js Node.js or FastAPI Mobile applications Role-based permissions Multi-tenant SaaS architecture Complex business workflows Deliverables We're looking for a team that can own development from beginning to end, including: Architecture Backend development Frontend development Database design Mobile application API integrations QA DevOps Deployment Documentation Project Scope The specification currently outlines a four-phase roadmap consisting of: Foundation platform Warehouse operations 3PL functionality Enterprise scaling features The full project is estimated to span approximately 12–16 months, although we intend to build incrementally with clearly defined milestones. Phase 1 will focus on delivering a working Shopify-connected WMS that can receive inventory, manage bins, process orders, and fulfill shipments.