[bobzimuta]

The next step after ensuring you're doing the basics (cdn, minimizing data over the wire, etc) for us was to throw the entire site behind varnish. Set a "don't cache" cookie if users login, add a comment, etc. so that their changes are visible immediately.

We took a slow site running on hardware, put it on EC2 (slower hardware obviously), and with varnish are saving about 60% cost of hosting, and decreased page load time on some of the popular pages by upwards of 50%, all for minimal engineering effort.