Problem
How do you handle a transaction that spans multiple microservices, each with its own database?
Be ready to discuss
- Saga pattern: choreography (event-driven) vs orchestration (a coordinator), and compensating transactions to undo partial work.
- Two-phase commit (2PC): how it works and why it scales poorly / blocks under failure.
- Eventual consistency and designing idempotent, retry-safe steps.
- The transactional outbox + CDC pattern to publish events reliably with a local commit.