Caching and CDNs

Part of the Web course

Your homepage takes 900 milliseconds to build, and it builds the same thing for the ten thousandth visitor as it did for the first. Somewhere in that number is the single largest performance win available to you, and it requires no faster database, no rewrite, and no extra server: just an agreement with the browsers and networks between you and the user about which responses can be reused and for how long.

A request leaves the user's machine and can be answered at any of three points before it ever reaches your server. ...