[hinkley]

There's loads and loads of literature on this, but I never felt it as strongly as with Angular. No matter how you represent the data, you want one layer of the code to be responsible for final dispensation on the organization and data munging (maps to arrays, arrays to maps, undefined -> empty set, etc). Everything else in the system should treat those fields in a homogeneous manner, and if you don't like the way the data is shaped, you know exactly where the problem is.

ORM or not, there's going to be a clear spot in the code where any mismatches between the backend and the frontend will be found. Or you're going to play whack-a-mole forever, and ramping up new employees will be a strain.