Race-Safe Idempotent POST Endpoints in Go

When a client sends a POST /products request, the server creates the product, but if the load balancer drops the connection before the response is sent, the client experiences a timeout and retries the request, leading to duplicate products. This common failure mode highlights the necessity for an idempotency key, which allows the server to ensure that the same key does not execute the operation multiple times. This article discusses the implementation challenges and solutions for race-safe idempotent endpoints in Go.