Connection pool saturation
Your monolith talks to 6 microservices through a shared HTTP client connection pool (max 200). At 19:40 the whole app's p99 goes to 30s and error rate spikes across ALL endpoints, even ones unrelated to search. Dashboards: the recommendations service (one of the 6) has p99 of 28s after a deploy at 19:35; the shared pool shows 200/200 connections in use and a growing wait queue; thread pool on the monolith is saturated. Other 5 downstreams are healthy. How do you triage and mitigate?
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 40 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.