A bit of a plug, but if you wish for something that has the Postgres reliability, the taste of nosql but with strong typing and a json output a la graphql, give a try to edge db: https://edgedb.com The team behind it is awesome (one is a python core dev), and it's a FOSS, but they have been using it internally for some time.
I feel like this is close to what I'm looking for but not quite there in terms of minimal boilerplate backend. Basically what I want to do is write a GraphQL schema and have that be the ultimate source of truth. The schema then should generate the full DB (honestly I don't even care if it's SQL, NoSQL, etc. the idea is that part is abstracted away). Then the schema can generate fully typesafe queries for the front en…
E.G: Django ORM will let you define the schema, and be the single source of truth for you DB and your REST API.