Outbound connections fail under load
A backend service that fans out to a downstream API starts intermittently failing to make outbound connections under peak load: logs show 'cannot assign requested address' (EADDRNOTAVAIL) on connect, and request error rate spikes during traffic peaks then recovers in troughs. The host is not CPU- or memory-bound. `ss -s` shows tens of thousands of sockets in TIME_WAIT toward the downstream's IP:port. A recent change replaced a pooled/keep-alive HTTP client with one that opens a fresh connection per request. The ephemeral port range is the default. Triage and fix.
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.