About This Architecture
E-commerce order and payment sequence diagram orchestrating four phases: order placement, payment initiation, VNPAY gateway processing, and asynchronous callback handling. User submits order through React frontend, triggering Node.js backend validation, MySQL persistence, and VNPAY payment request with dual callback mechanisms (IPN and browser redirect). The architecture demonstrates secure payment flow with explicit error handling—failed transactions (responseCode != 00) update order status and notify users immediately. Fork this diagram to customize payment gateway integration, add retry logic, or adapt for alternative processors like Stripe or PayPal.