- Using `JOIN`s (with correlated subqueries and JSON) has been around for a while now via a `relationLoadStrategy` setting.
- Prisma has a Rust service that does query execution & result aggregation, but this is automatically managed behind the scenes. All you do is run `npx prisma generate` and then run your application.
- They are in the process of removing the Rust layer.
The JOIN setting and the removing of the middleware service are going to be defaults soon, they're just in preview.