Rate limit bucket collision
Right after a config push to your Envoy edge proxies, legitimate users start getting 429 `Too Many Requests` even at normal, low traffic. The Envoy dashboards show the local rate-limit filter rejecting a large fraction of requests, and the rate-limit counter is keyed on a header that's the same for everyone behind a corporate NAT — so thousands of distinct users share one bucket. The intended limit was per-API-key; the config push changed the descriptor key. Error rate is high but backend CPU is low and there's no real overload. How do you 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 35 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.