How would you answer an interview scenario involving AWS Lambda in AWS?

For an interview scenario involving AWS Lambda, I would first clarify the business goal, scale, constraints, and the failure or quality attribute the interviewer wants to explore. AWS Lambda is a serverless compute service that runs code in response to events. In this scenario, for an SQS-triggered Lambda that processes payments, explain batch size, retries, partial batch failure, idempotency, DLQ handling, and concurrency controls. For production, keep handlers small and stateless, reuse clients safely, configure concurrency, retries and DLQs, make event processing idempotent, and monitor duration, errors, throttles, and cold starts. 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.