You'd get more benefit if you're developing API where random others are consuming your code for them to use API properly.
But still, it can still save you from obvious mistakes even for a one man project.
But still, it can still save you from obvious mistakes even for a one man project.
Using GraphQL to type your in-process API would be overkilled and would require quite a bit of contortionism, and while you can share same TypeScript types between your end-points interfaces (and can be a good first step), inter-process communication is better expressed with something like GraphQL or Protobuf.