Idempotent
ELI5 — The Vibe Check
Idempotent means you can do the same thing multiple times and get the same result as doing it once. Pressing an elevator button a hundred times still just calls it once. DELETE a resource twice — second time it's already gone, no explosion.
Real Talk
An idempotent operation produces the same result when applied once or multiple times. In HTTP, GET, PUT, and DELETE are idempotent; POST is not. Idempotency is critical for safe retries in distributed systems, event processing, and API design.
When You'll Hear This
"Make the payment endpoint idempotent so retries don't double-charge." / "Database migrations should be idempotent so they can be re-run safely."
Related Terms
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Side Effect
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