One endpoint parses a large uploaded CSV in memory. When it runs, unrelated endpoints in the same service also get slow. Explain.
Answer it out loud before you open anything. The value of the flags below is in comparing them to what you actually said.
The situation behind the question
A Node service. The CSV endpoint is called a few times an hour. During those calls, health checks occasionally fail and p99 across every route rises.
What it is really testing
Whether the candidate understands the runtime's concurrency model well enough to explain cross-endpoint interference — and whether they know the explanation is runtime-specific rather than universal.