In my experience developing In-House custom software it’s more “Managers” and “End-users”: basically the requirements for the software that’s developed are defined by the manager overseeing an area and hence based on their point of view of the business process they oversee, which is often not at all the same point of view as the people working in that process.

I’ve seen again and again software being made exactly to the spec provided by team/area management and then turning out to have lots of problems for the actual users to use.

In my experience the best results come from having the developers talk directly with the end-users, even if the language the devs tend to speak and their preconceptions at first don’t match those of the end-users.