OTOH, if you use Flow or Typescript, it is amazing to be able to share type-safe interfaces across the stack (not code). I suppose you could get this from any compiled-to-JS language too.
If you’re not _very_ careful with your software architecture, you can inextricably tie your frontend and backend applications together. Depending on the size of your product, or why the growth plans are for that particular frontend/backend app end up being, this might not be a problem.
If it becomes one, though, then every bad technical design decision made in that `common` set of modules or packages ends up hurting you as it gets unspooled from (at least) two components that likely have very different architectural idioms.
The remaining coordination issues can be solved by documenting or using e.g. a '@Deprecated' decorator in Typescript. And, of course, you can always just remove a field to see where the code has dependencies on it (where code breaks during compilation).
The concerns about shared code may apply in some cases, but the global schema is not one of them, in my experience. I do agree it takes a bit of extra thinking to do this correctly but it's really not that difficult.