In sum, Joseph argues for a four-point approach to achieving maximum performance in your web-app:
- Be lazy: Don’t load or do things before you need to; maybe you won’t need to load or do them at all.
- Be responsive: Make things happen quickly. If you can shave 100ms off of an interaction by responding to a mousedown event instead of a click event, do it.
- Be pragmatic: Frontend engineering is hard enough. Don’t make it harder than it needs to be.
- Be vigilant: Blank web pages are fast. Web pages become slow because you put stuff in them; slowness is your resonsibility. Vigilance is required to prevent slowness.
http://josephsmarr.com/2007/08/29/my-ajax-talk-is-now-on-yui-theater/