NetTuts.com has posted part eight in their series looking at refactoring legacy code - Inverting Dependencies for a Clean Architecture. In this latest post they move away from just refactoring the code and start to look more at fixing the architecture of the application.
Old code. Ugly code. Complicated code. Spaghetti code. Gibberish nonsense. In two words, Legacy Code. This is a series that will help you work and deal with it. It's now time to talk about architecture and how we organize our newly found layers of code. It's time to take our application and try to map it to theoretical architectural design.
They look at the current structure of the code (well, of their refactored version) and how to apply the Dependency Inversion Principle (part of the SOLID methodology) via interfaces. The code is included for the refactor as well as tests to add to their "Golden Master" test suite to ensure continued correct functionality.