File descriptor leak in new integration
Over ~6 hours after a deploy, your service slowly degrades: new client connections start getting refused, logs show `Too many open files` and `accept: too many open files`, and the process's open file-descriptor count (from `/proc/<pid>/fd`) has climbed steadily to its 65536 `ulimit -n` ceiling and plateaued. Request rate is flat and normal — this isn't a traffic event. Restarting an instance fixes it for a few hours, then it recurs. The deploy added a new outbound integration that makes HTTP calls. How do you 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 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.