When it comes to Web API best practices, idempotency is a pretty easy one to explain. An idempotent API operation is an operation that produces the same effect no matter how many times it is executed. Done, right? Now you know how to use that in your API design, how to explain it to your boss, and how to justify why it’s important. Right?
Well, probably not. That was a definition, not an explanation, and certainly not a justification.