A service saves an order to the database and then publishes an "order created" event to a message broker. What problems can come up here, and how do you solve them?
~4 min by voice
How to approach it
The interviewer wants to see whether you spot the dual write problem, the lack of atomicity between the database and the broker, and whether you can solve it with a Transactional Outbox while understanding the delivery guarantees (at-least-once) and what they mean for consumers.
The interviewer will ask this question and listen. Think out loud and ask for a hint if you need one. When you're done, pause or tap “That's my answer”. In about a minute, your score and the points you covered show up here.