Deploying your webapp is an important part of the web development equation - your client's site isn't going to attract a lot of attention sitting in your local dev directory. Deployment concerns tend to fall to the bottom of the priority list, though, and the end result tends to be kludgy, hastily thrown-together deployment scripts; and because they are so kludgy and, often, time consuming, when time crunches threaten, a developer may resort to making changes directly on the remote server that need to be (but sometimes never are) backported to the code living in your version control.