FrontendHaltNetworking·Advanced·Conceptual·1 min read
Is PATCH idempotent?
Short interview answer
Not necessarily — it depends on the semantics of the specific patch operation. A PATCH that sets a field to an exact value is idempotent, but one that increments a counter is not, since repeating it changes the result each time.
Key takeaway
Explain the underlying mental model clearly, then support it with a concrete example and its trade-offs.