Failover connection pool spike
A managed-Postgres failover just promoted a standby (took ~25s). Right after the new primary came up, your API started returning 500s in waves and Postgres logs are full of `FATAL: sorry, too many clients already`. You run PgBouncer in transaction mode in front of ~40 app instances. `pg_stat_activity` on the new primary is pinned at `max_connections`. The failover itself completed cleanly; the database is up. Connections keep spiking, dropping, and spiking again. 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.
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.