I'm pretty in love with schema-driven development with https://www.graphile.org/postgraphile/. I generate a graphql schema from postgres, and code models/serializers from that.

Currently using migra and some custom scripts for migration management - will check out automigrate.

The main issue I've had with developing a large backend in pure SQL is that you end up having to piece together custom scripts, migration tools, etc. to add features your database/SQL doesn't provide, like modules and higher order abstractions. So I'm actually considering switching to something like SQLAlchemy simply for that