Thanks for joining the conversation @nodkz! And great work on graphql-compose — wow, there’s a lot of functionality under the hood. 
This definitely reinforces that there’s an interesting path for an experiment using Mongoose + graphql-compose-mongoose.
Redwood’s GraphQL API has a unique design that automatically maps resolvers from Redwood Services to SDL. If it’s of interest, here’s more information about how this works:
- How Redwood Works with Data (from the Tutorial)
- Related API Package Code
- Example using a Third Party API with the Redwood API
Another reference example is this Forum Thread about using FaunaDB with Redwood. Take a look at the code examples for:
api/src/graphql/posts.sdl.jsapi/src/lib/db.jsapi/src/services/posts/posts.jsapi/src/functions/graphql.js
Seems like we could be close to having all the Mongo pieces we’d need? Again, I’m just not sure how mapping the resolvers would work out (yet).