How would you answer an interview scenario involving Amazon SQS and SNS in AWS?

For an interview scenario involving Amazon SQS and SNS, I would first clarify the business goal, scale, constraints, and the failure or quality attribute the interviewer wants to explore. Amazon SQS provides durable message queues, while Amazon SNS provides publish-subscribe fan-out messaging. In this scenario, for an order-created event consumed by billing, inventory, and notifications, explain SNS/SQS topology, retries, DLQs, duplicate handling, and message versioning. For production, make consumers idempotent, configure visibility timeout and DLQs, use SNS-to-SQS fan-out when subscribers need durable independent queues, and monitor age and failure metrics. I would then explain the main alternatives and tradeoffs, identify likely failure modes, and describe how I would validate the solution through testing, observability, security controls, and recovery or rollback planning.