The typing is interesting as I have been leveraging Typescript as an IDL for code generation between Go backend and TypeScript frontend. (GraphQL and gRPC were not expressive enough to define services, DTOs and JSON schema forms). Parsing Typescript's AST is simple. My guess is they generate code based on statically analyzable type arguments. I'm eager to try their approach. I am currently parsing jsdoc comments and tags for metadata which doesn't benefit from Typescript's checker.

jooq is awesome. I was using that with DropWizard way back when. Now I'm just Go.