Indeed, one of the main selling points of DBOS. All the functionality of Temporal without any of the infrastructure.

Ah I don't know if I would agree with that. Temporal does a lot of stuff; we just don't happen to need most of it and it's really heavyweight on the database side (running low 500 or so workflows/second of their own 'hello world' style echo benchmark translates to 100k database ops/second..

DBOS is tied to Postgres, right? That wouldn't scale anywhere near where we need either.

Sadly there aren't many shortcuts in this space and pretending there are seems a bit hip at the moment. In the end, mostly everyone who can afford to solve such problems are gonna end up writing their own systems for this.