Pretty much anything with an API can be hooked up to toddle. I have seen Make being used in one of the toddle live builds, so Zapier and n8n should be fairly straightforward, although I haven’t used them personally.
There’s no direct database hookup from toddle afaik but it is possible to use other tools to handle that connection, so worth having a look at other backend tools like Fastgen, BuildShip and Comnoco, etc., if you want to look at that type of thing.
Personally, I use Supabase, which is Postgres and a few here also use Xano.