The backend checklist before an exchange goes live

The public trading interface is only one small piece of an exchange. Before a launch, the boring operational routes deserve the same design attention: deposits that do not arrive, withdrawals that need review, and accounts that need a human decision.

Make state visible

Every important operation should leave a clear trace. A support or operations teammate needs to see what happened, what is waiting, and which service made the last decision without reading application logs.

Design the recovery path

External systems fail. Wallet daemons are delayed, webhooks arrive twice, and an upstream API may time out after accepting a request. Idempotency, reconciliation, and deliberate retry behaviour are product requirements, not implementation detail.