Earlier quoted context omitted.
There are a lot of solutions out there where you can share your datatypes between the client and server now though, and it's great!
This comment would be more helpful with some examples. I’m personally very curious what the leading solutions are. I’ve worked with one involving GraphQL but that’s about it.
By the way, echoing some discussion above, we migrated from Express to NestJS, and it was an excellent decision.