Topic
Designing money-movement systems where integration calls, settlement reporting and cash evidence have distinct owners.
UK software seller to pubs and bars turns on Stripe Managed Payments, at 3.5% over card fees, only for customers in the 27 EU countries. Leaving UK buyers out keeps the fee, and 20% VAT, off home sales that do not owe tax yet.
Reality
Retried Buy clicks get the original order back in a dev.to guide that commits each order with its attempt key in one SQLite transaction. A disabled button only cuts double-clicks, and the guide's available text ends before it covers charging the card.
Reality
Checkout metrics in a dev.to guide are recorded only after commit or rollback, and its rollback rule needs 20 attempts and a 5% failure rate. Keeping telemetry out of the transaction protects the failure record, though the default rule calls for rollback on a single failure in 20 attempts.
Reality
A lost response looks exactly like a failed request from the client. That single ambiguity is why any API that moves money has to treat a duplicate submission as normal traffic.
Reality
A dev.to essay argues the usual reconciliation fix, deciding which system is authoritative, destroys the evidence you need. The design should preserve the mismatch until something closes it.
Reality