In the article you didn't need to do a re-write of the entire site, just a re-design of the UI. You needed to add functionality but you could have left the old

In the article you didn't need to do a re-write of the entire site, just a re-design of the UI. You needed to add functionality but you could have left the old working functionality. Another case for a re-right is when the project uses old technology that is hard to maintain with the people you have. Re-writing the system in a framework that your team understands will take less time than trying to understand another framework.