Postgres queue tech is a thing of beauty, but far from mainstream. The scalability cult has decreed that there are several queue technologies with greater “scalability” than Postgres, and for that reason alone, Postgres isn’t suitably scalable for anyone’s queueing needs.
Postgres queue tech consists of two parts: announcing and listening for new jobs (pub/sub) and mutual exclusion (row locks).
I’m aware that these mean specific things that are not exactly “queue” or “queue processing”.
Neoq queues can be in-memory, Postgres, or Redis (contributions for your favored boring tech welcome!).