Abuse account signup surge
Your signup dashboard shows new-account creation up 25x in 6 hours, all from a handful of cloud ASNs, using disposable-email domains and sequential usernames. These accounts immediately call your free-tier LLM completion API at the per-account rate limit, burning a large GPU bill, and a few are scraping your private 'people search' endpoint. Conversion to paid is zero. Your fraud queue is clean (no chargebacks yet) so finance hasn't noticed, but cost-per-hour just doubled. How do you triage and shut down this abuse without harming legitimate new users?
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.