Transactional Outbox

Transactional Outbox Keeps Database State and Events Aligned

A service often needs one operation to change database state and emit an event. An order may move to paid while OrderPaid must reach a message broker. Those two writes cross different systems, so a normal database transaction cannot make both commits atomic. Writing the database first leaves a gap: the process can stop after commit but before publishing. Publishing first creates the opposite gap: consumers can observe an event for a database change that later fails.