While building web apps, one thing I preach (and mostly stick to) is: build the API first and use it to build your app. This API could be simply the core code f

While building web apps, one thing I preach (and mostly stick to) is: build the API first and use it to build your app. This API could be simply the core code for it (say a set of functions), with error checking and everything, that you use to build your app. Later, you wrapit in a thin I/O layer for use over HTTP for external use.