It has been proven by numerous sites that EPiServer CMS can handle huge amounts of content. Doing so does bring a few challenges though. Here's a few few patterns that I've identified when it comes to building large scale EPiServer sites with great performance.
"In this post I’ll describe a few common patterns when integrating EPiServer CMS sites with external systems with focus on fetching and displaying content."
An introduction to Inversion of Control, using the Dependency Injection and Service Locator patterns, along with simple examples in C#.