Custom B2B Storefront & App Development

We are building the customer-facing layer of a specialized B2B platform for on-demand additive manufacturing. Engineers will use this storefront to upload CAD designs, receive AI-powered Design for Additive Manufacturing (DfAM) analysis and instant quotes, compare options, place orders with approval workflows, and track production with full traceability. This is not a standard Shopify theme customization or generic DTC store build. It requires deep integration between Shopify and a custom backend platform, custom app development, B2B features, and handling of complex quoting/ordering flows. The engagement covers the MVP of the Shopify layer. Strong results can lead to ongoing work on future phases. MVP Scope (Shopify Layer) - Modern buyer storefront (Shopify theme or headless Hydrogen/Remix recommended) - Custom Shopify App that handles: - CAD file upload and secure handoff to backend - Display of AI-generated DfAM analysis and multiple supplier quotes - Quote comparison, selection, and order creation - Company/account management and multi-user approval workflows - B2B-focused features: company accounts, custom price lists/quoting, draft orders, net payment terms, and role-based visibility - Checkout customization or extensibility (Shopify Functions / Checkout Extensibility) to support complex order data and approvals - Webhooks and robust two-way sync between Shopify and the custom backend (orders, status updates, digital thread events) - Clean, well-documented code with proper error handling, logging, and security practices Later phases may include deeper personalization, advanced configurators, post-processing add-ons in checkout, and enhanced analytics. Key Technical Challenges - Building a reliable custom Shopify App with secure file handling and backend API integration - Displaying dynamic, AI-generated quotes and analysis inside the Shopify experience - Implementing B2B workflows (approvals, company accounts, draft orders) that sync cleanly with external systems - Maintaining performance and data consistency across Shopify and the custom platform - Production-grade practices: idempotency on syncs, proper error recovery, audit-friendly logging, and security for proprietary design files Tech Preferences Strong experience with Shopify Plus features, Custom App development (including billing API, webhooks, and Admin/Checkout extensions), and either traditional Liquid themes or headless (Hydrogen + Oxygen / Remix + Storefront API) is highly valued. Experience integrating Shopify with external APIs or complex backend systems is essential. We are open to your architecture recommendations with clear reasoning. Must-Have Experience - 4+ years professional Shopify development with production projects - Demonstrable experience building Custom Shopify Apps and/or headless Shopify storefronts - Strong integration skills (REST/GraphQL APIs, webhooks, reliable data synchronization) - Experience with B2B Shopify features (company accounts, custom pricing, draft orders, approval workflows) - Excellent communication, proactive updates, and ability to work with a separate backend team - Clean code practices, testing where critical, and proper documentation Nice-to-Have - Prior work on manufacturing, industrial, or quoting/configurator-type Shopify projects - Experience with Shopify Functions, Checkout Extensibility, or complex checkout customizations - Familiarity with file upload/processing flows or 3D/CAD-related interfaces - Experience working alongside custom backend teams (not just standalone Shopify stores) Engagement & Timeline MVP delivery targeted in 6–10 weeks with clear milestones and regular demos. Open to hourly or milestone-based pricing. There is strong potential for continued work on future phases for the right partner. How to Apply To help us move quickly with serious candidates, please include in your proposal: 1. A brief summary of why this project interests you and one relevant past project (with link or specific details) involving Custom Shopify App development, headless storefronts, or complex B2B integrations. 2. High-level thoughts on how you would structure the Shopify App + storefront integration with an external backend (key components, data flow for quotes/orders, error handling, and security for design files). 3. Your availability over the next 3 months and preferred pricing model (hourly rate or estimated range for the MVP scope). 4. Confirmation that you are comfortable with detailed code reviews, GitHub collaboration, and proactive communication. We value specific, real-world examples and clear technical thinking over generic proposals. Thoughtful applications will receive priority. Looking forward to reviewing strong submissions.