AJAX is hard. Even now we're just starting to see the depth and breadth of functionality that AJAX can support. This session will present possibly contentious lessons learned over three years of programming an intricate AJAX application. We'll discuss, at a macro level, why AJAX development is surprisingly different from traditional applications programming. We'll offer concrete data to illustrate areas where conventional wisdom about AJAX is mistaken. And for the technical attendees, specific areas where it is best to discard standard software design practices and do the opposite will be detailed.