In order to continue down the path of heavily abstracting all our objects, it is important to consider how coupled your application is to the .NET framework, or other frameworks, or third-party tools that you don't have control over. This may not seem important initially, but you will eventually find yourself in a place where the framework that Microsoft provides you with may not cut the mustard any more.

A quick example of this might be the caching objects that are provided. While these work great out of the box, they don't really scale well. What happens when you build a site that becomes so popular that you need to do everything possible to eek out that last bit of performance? The first response is usually to just go to a web farm. The next response is to add more boxes to the farm. The third response is to add more boxes to the farm…huh?

How often can adding more hardware to address performance issues be a standard response? At some point in time you will have...