Connection charset mojibake corruption
Support reports user names and addresses with accented and non-Latin characters now show as garbled mojibake (e.g. 'José' → 'José', '北京' → question marks) for records created in the last 3 hours. Older records are fine. Dashboards: error rate normal, no failed inserts. Context: a service was redeployed 3 hours ago after a connection-library upgrade; the MySQL columns are `utf8mb4`, but the new driver's default connection charset is `latin1` (the old driver defaulted to `utf8mb4`). How do you triage, stop further corruption, and recover the already-corrupted rows?
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.