How would you handle a practical scenario involving API Gateway in Microservices Architecture?

For a practical scenario involving API Gateway, I would first clarify the business goal, scale, constraints, and the failure or quality attribute being tested. An API gateway provides a controlled entry point for clients and can handle routing, authentication, throttling, aggregation, and cross-cutting policies. The scenario centers on a mobile app calls many services directly; explain how an API gateway can simplify the client while avoiding an oversized gateway layer. For production, keep the gateway focused on edge concerns, secure it, scale it independently, use rate limits and observability, and avoid hiding unstable internal contracts behind excessive transformation. I would then compare the main alternatives and tradeoffs, identify likely failure modes, and explain how I would validate the solution through testing, observability, security controls, and recovery or rollback planning.