POSTGRES LISTEN/NOTIFY DOES NOT SCALE

Summary from the TLDR Web Dev newsletter

Recall.ai experienced Postgres downtime due to heavy write loads from thousands of meeting bots. An investigation showed that Postgres' LISTEN/NOTIFY feature acquired a global database lock during transaction commits, serializing them and causing a bottleneck. Load tests confirmed that removing LISTEN/NOTIFY allowed the database to fully utilize CPU cores and handle load spikes effectively.