I'd guess that any meaningful answer has to be based on the reasons you are using the techniques. Interfaces and a framework in a team environment and managed in a central way can be, as I found, a very good way of managing the code people write and also a extremely useful mechanism that enables the interaction of code written in different languages and by different teams. The ability to have another person write a test based on an interface is also very useful. If you're working by yourself some of the benefits interfaces can bring as just mentioned might be regarded as wasted coding time but perhaps bring benefits that are worth the extra code at design and debug time and also in introducing some discipline. However if you're writing code that you expect others to have to work with in the future you're probably contributing to their being able to understand it relatively quickly - though are probably demanding a fair level of expertise from those future people by your selection of framework etc. Also if your code is part of a generic platform used across applications then using interfaces etc. probably contributes to that. However if its for a specific instance then as you suggest you may be adding generality that's not required. From another perspective i.e. yours, rather than 'the company' are you learning skills and methods that improve your standards - it can get very boring doing the simple things without new approaches. I suppose you've got to way the pros and cons on each technique from say a client, company(over say a N year period) and personal perspective to reach a real conclusion.
