Synchronized reconnect storm
A 30-second network blip in one AZ drops ~200k persistent WebSocket connections to your realtime gateway. The moment connectivity returns, the gateway fleet's CPU and accept-queue saturate, the auth service behind it gets a synchronized request spike and starts timing out, and the whole reconnect cycle keeps failing and retrying in lockstep — the dashboards show CPU oscillating in sharp synchronized waves every few seconds. The clients use a fixed 1-second reconnect interval. How do you triage and break the cycle?
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.