Racing a Next.js API route: coupon abuse with Prisma and SQLite

OopsSec Store validates a coupon and increments its counter in two separate database calls. Send enough concurrent requests and several slip through the check before any of them completes the increment. The OopsSec Store homepage advertises FLASHSALE : 50% off, single-use.

Source: [Dev.to](https://dev.to/oopssec-store/racing-a-nextjs-api-route-coupon-abuse-with-prisma-and-sqlite-3gma)