Senior CS-Cart Developer Needed (Vendor Dashboard + Shopify Integration)

Job Title Senior CS-Cart Backend Developer (Vendor Portal + Shopify Integration) – Long-Term Opportunity Job Description We are looking for a highly experienced CS-Cart developer to build the backend of a large multi-vendor marketplace. This is NOT a beginner project. You must have real commercial experience with CS-Cart, building custom modules, vendor portals, workflows and API integrations. We are looking for someone who can move quickly, make good architectural decisions, and require minimal hand-holding. Current Situation Existing business with thousands of products and multiple vendors. Shopify will remain our customer-facing storefront for Phase 1. CS-Cart will become our operational backend. The two systems will need to work together while we transition. Phase 1 Scope Build a vendor management backend including: Vendor dashboard Vendor login and permissions Product management Update prices Update images Update descriptions Inventory management Admin approval workflow before product changes go live Vendor order management Order status updates Mark orders as released/picked up Multiple users per vendor if required Notifications between admin and vendors Shopify integration for products and orders Clean, fast, professional interface Required Experience Please do not apply unless you have: 5+ years CS-Cart development experience Experience building custom CS-Cart add-ons/modules Strong PHP MySQL REST APIs Shopify Admin API Git Experience integrating CS-Cart with Shopify Excellent English communication When Applying Please include: Links to CS-Cart projects you've built. Explain exactly what your role was. Screenshots or demo access if possible. Experience integrating with Shopify. Your estimated timeline for Phase 1. Your fixed-price quote for Phase 1. Confirmation that all source code belongs to us upon completion. Important We are not looking for an agency that outsources work to junior developers. We want to work directly with the developer who will build the system. Screening Questions How many CS-Cart projects have you completed? Have you built custom vendor portals before? Please provide examples. Have you integrated CS-Cart with Shopify? Explain how. What is the largest marketplace you have worked on? If you started tomorrow, how long would Phase 1 take? What would your fixed price be for Phase 1? Will you be doing the development yourself? We are only interested in developers who have already built production CS-Cart marketplace solutions. If your experience is mainly with WordPress, Shopify themes, or general PHP development, please do not apply