The biggest thing that companies miss when they're building SaaS applications is that the network fucking matters. I'm talking from a internet-connectivity perspective. The view here is that you can take any ol' 'enterprise' ISP and put your servers on it, and you'll be good to go.<p>Unfortunately, no two ISPs are equal, which often times, forces you to purchase from both. TCP implementations of OS's today have been tuned for the late 90s, which requires dives under the hood to tune them for today's TCP.<p>When your application performance is pegged on the network the, most people say just put static content on a CDN - and that works. But for dynamic content, most people think you're screwed. While you can't main any gigantic gains on it, there are a few things you can do for speed: TCP tuning, compression, path optimization, and pipelining.