With that experience behind you, would you have feedback for Chancy[1]? It aims to be a batteries-included offering for postgres+python, aiming for hundreds of millions of jobs a day, not massive horizontal worker scaling.

It both polls (configurable per queue) and supports listen/notify simply to inform workers that it can wake up early to trigger polling, and this can be turned off globally with a notifications=false flag.

[1]: https://github.com/tktech/chancy