Redis

What Is Real-Time Inventory Synchronization? Real-time inventory synchronization is the process of propagating stock count changes from the system of record (database) to all sales channels — web storefront, mobile app, WMS, ERP — in sub-second time. Instead of batch ETL jobs that run every hour, a CDC + Kafka pipeline streams every committed stock change as an event, eliminating overselling and stale stock displays. Handling this during a flash sale — where thousands of users attempt to purchase a highly contested SKU simultaneously — is a pinnacle architectural challenge. Traditional synchronous database updates collapse under lock contention. ...

Answer-first: Explore the architecture of a real-time Surge Pricing algorithm. Discover how Uber utilizes the H3 spatial index, Kafka, and Flink to calculate dynamic pricing. Why is it that every time it rains, ride-hailing fares double, or even triple? It’s not a human operator manually adjusting the prices behind a desk. Rather, it’s the result of an incredibly sophisticated Stream Processing engine running in the background executing the surge pricing algorithm. ...

Answer-first: How Shopee engineers prevent crashes during 11.11 flash sales: rate limiting, Redis inventory locks, traffic shields, and microservices resilience. 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. ...