Architecture & DesignIntermediate
Idempotency
Pronunciationeye-dem-POH-ten-see
Definition
A property of an operation: doing it many times gives the same result as doing it once. This makes retries safe.
Where you hear it
Payments, webhooks, retries, and background jobs.
Examples
Send an idempotency key so retries cannot charge the customer twice.
Make the job idempotent because the queue may deliver it twice.
Common mistake
Building a "charge" endpoint without an idempotency key. If the network drops, the client retries and pays twice.
Keep exploring
More in Architecture & Design