Design Patterns · Senior · Question 51 of 75

What problem does the Transactional Outbox pattern solve?

✓Correct answer: Saving data and publishing an event atomically: the event is written to an outbox table in the same transaction and sent later
2Sending emails from the browser
3Caching outgoing HTTP requests

Explanation

Without it, a crash between "save" and "publish" loses events or publishes events for unsaved data. Consumers must be idempotent.

Further reading

microservices.io: Transactional outbox ↗

Test yourself

Take the Design Patterns · Senior quiz: questions and options are shuffled, and you get a review of your mistakes at the end.