This is true for systems where there is a well-defined protocol between GUI and servers and a proper versioning process in place, i.e. most "old-school" client/

This is true for systems where there is a well-defined protocol between GUI and servers and a proper versioning process in place, i.e. most "old-school" client/server systems. I expect lots of people on HN are working on systems with very tight coupling between client/GUI and server and no proper versioning between them, as is common in web applications. Hence the replies to the contrary: you're probably from quite different worlds :) (Now, I personally think that maintaining sound versioning practices is a good idea even if you do have tightly coupled control of both the client and the server side. But that may just be me...)