Postgres LISTEN/NOTIFY has a bad reputation thanks in part to a popular blog post asserting it does not scale . If that were true, it would be a shame, because LISTEN/NOTIFY is a powerful tool, allowing you to use your Postgres database for low-latency durable notifications, streams, and pub/sub. The accusations aren’t wrong: NOTIFY has unintuitive and undocumented performance characteristics arising from its use of a global lock. But “unintuitive behavior” is not the same as “not scalable.” In this blog post, we’ll show how we optimized LISTEN/NOTIFY-backed streams at scale, achieving 60K writes per second on a single Postgres server with millisecond-scale latency. Low-Latency Streaming with LISTEN/NOTIFY The basic design of Postgres-backed streams is simple: create a streams table where each stream chunk (for example, an LLM response token) is a new row, then write to streams by inserting into the table. ‍ The tricky part is reading from the stream because you don't know when the next chunk will arrive.…