Yeah, if your projects are so tightly coupled that you have to work on them in the same Solution, then you may as well Join them most of the time. Another bit,

Yeah, if your projects are so tightly coupled that you have to work on them in the same Solution, then you may as well Join them most of the time. Another bit, I would generally have the Interfaces project include the client... so one DLL for other solutions to import from, and it doesn't really add much of anything to the Server implementation. That's just one example. Another is separating API controllers, DAL, BLL into separate Projects... there's rarely a practical reason for this, and in practice just adds indirection and complexity for very little real world value. But hey, "Enterprise" patterns and all.