Lambda cold start during ramp
Your API is a Lambda behind API Gateway. After a quiet overnight period, the 08:00 traffic ramp causes p99 to spike to 4–8s for the first few minutes while p50 stays at 120ms. CloudWatch shows `Init Duration` appearing on a large fraction of invocations during the ramp, `ConcurrentExecutions` climbing fast, and a few `Throttles`. The function loads a large ML model and opens a DB connection in its init code. No deploy happened. How do you triage and reduce the morning latency cliff?
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 30 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.