On-callMediumoc-g294

Subject Api quotaLevel Mid–Senior~35 minCommon in Reliability & on-call interviewsIndustries Technology

Question

Your integration with a third-party geocoding API has a generous daily quota you've never come close to. At 09:00 you start getting 429 'daily quota exceeded' — at 9am, with most of the day's traffic still ahead. Dashboards: your outbound call volume to the geocoder spiked 50x starting at 08:30, but your inbound user traffic is completely flat and normal. No quota or pricing change from the vendor. You deployed a small change to the geocoding client last night. How do you triage and mitigate?

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.

Learn the concepts

Diagram & narrate the incident

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Run or narrate your approach, then ask the coach.