Why Sub-50ms API Responses Are Critical for Checkout: Stopping Codebroker Fraud, Single-Use Coupon Leaks, and SMS Abuse
https://xn--se-wra.com/blog/replace-rigid-coupon-engines-a-step-by-step-guide-for-technical-decision-makers-at-retail-10428
Checkout drop-off and fraud windows: why milliseconds change whether a sale is saved or stolen When a customer clicks "Pay" during checkout, the system has only a few hundred milliseconds to validate payment, apply discounts, and block abuse