Your question is Streams, Concurrency, and Observability. 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).
Explain how you use Java Streams and concurrency in a WebFlux backend, and how you would monitor performance and resource usage with Prometheus, Grafana, and Datadog.