SecurePay Marketplace Platform

A growing marketplace client needed to move off a rigid off-the-shelf cart platform that couldn't support multiple vendors, custom commission rates, or the payment gateways their target market required.

Built a custom PHP/MySQL backend with vendor onboarding, per-vendor commission logic, and secure payment integration. Added rate limiting and input validation across every endpoint after an initial security review flagged gaps in the legacy system.

Launched with zero critical security findings in post-deployment audit. Vendor onboarding time dropped from days to under an hour, and the platform has processed thousands of transactions without a payment-related incident.