Disk full WAL accumulation
Your primary Postgres just went read-only / started rejecting writes with `ERROR: could not extend file ... No space left on device`. The data volume is 100% full. It filled fast over the last few hours. The `pg_wal` directory is enormous — far bigger than usual. You recently spun up a new read replica that's been having trouble staying connected, and there's a logical replication slot feeding a downstream analytics pipeline that's been broken for two days. Triage and mitigate without losing data.
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.