Shopee Flash Sale Architecture: Rate Limiting & Redis
Answer-first: Architecting flash sale systems requires preventing database overload using multi-stage rate limiting and Redis-based inventory pre-decisions. Traffic shields block duplicate requests, and asynchronous checkout queues decouple order submission from payment processing. What You’ll Learn That AI Won’t Tell You Multi-stage cache invalidation strategies that keep checkout fast. Handling concurrent Redis connections during million-user flash sales. At exactly midnight on 11.11, Shopee users across Southeast Asia and Taiwan simultaneously tap the same button. In the first 10 seconds of a flash sale, a single product page can receive requests from millions of concurrent sessions — all competing to purchase the same 1,000 units of inventory. One oversell, one server crash, or one database deadlock during that window results in a cascade of chargebacks, angry users, and front-page news headlines. ...