Vendor calls block and timeout
A service guards calls to a flaky vendor with a `Semaphore(50)` to cap concurrency. Over hours it slowly degrades: throughput to the vendor falls steadily, and eventually every call blocks on `semaphore.acquire()` and times out, even though the vendor itself is responding fine and your traffic hasn't increased. A graph of available permits trends downward over time and never recovers — like a slow leak — flattening at 0. Restarting the pod fixes it instantly, then it slowly leaks again. A retry/timeout change shipped two days ago. Triage and find the leak.
What a strong answer looks like
Stop the bleeding first (mitigate), then form hypotheses from real signals. Separate root cause from symptom, communicate status as you go, and close with what prevents a repeat.
0:00 of about 35 min
Which questions mattered is sealed until you submit. Telling you now would just be handing over the edge cases.
Run or narrate your approach, then ask the coach.