Korum chose detect-and-refund over strict locking to handle booking overflows

Korum, a casual sports match coordination app, deliberately avoids hard database constraints to prevent overbooking, opting instead for a detect-and-refund approach. A soft capacity check runs before a payment hold is created, while atomic database routines enforce the final confirmation and flag any overflow for refund review. This means brief overbooking can technically occur but is caught and reversed immediately rather than discovered manually later. The developer argues that for low-stakes, low-traffic scenarios the engineering cost of strict locking outweighs the rare failure risk, though he acknowledges stricter prevention would be necessary in higher-stakes contexts like airline seating. The system also handles duplicate Razorpay webhook deliveries safely, ensuring the same payment event cannot produce duplicate confirmations.