Your question is Scalable High-Concurrency Backend. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
Can you explain how you would design a scalable backend service to handle high concurrency and data integrity?
Assume the service supports online ML predictions and asynchronous event ingestion. Explain how you would make request handling, feature updates, model deployment, and persistence reliable under concurrent access. Address consistency, idempotency, overload behavior, observability, and degraded operation without assuming a particular cloud provider or database.