A service must save an order and publish an "order created" event, and never do one without the other. How?

Options

• ✗ Publish the event, then write the order
• ✗ Write the order, then publish the event
• ✓ Write the order and the event to an outbox table in one transaction; a relay publishes from it Correct
• ✗ Publish the event and let a consumer write the order later

Why

Either two-step order leaves a gap: a crash between the steps loses one side. The outbox makes both one database transaction; the relay (polling or CDC) publishes at least once, so consumers must deduplicate.

Review this in your daily deck → All cards in Consistency