One of the most important tools in securing high-performance web content delivery is caching. But when we talk about caching, we often refer to static content that never changes and doesn’t contain any personalized information. Dynamic content, which changes frequently and is often used to personalize web experiences, isn’t easily cached because it contains content specifically tailored to an individual user. 

The single most frequent question I get from people discovering Varnish is "Do you support request collapsing?". And I must admit, it always catches me off guard, because of course, it has been doing so for years, and it's a caching server, so that's a must-have, right? (Yes, yes it is.)

For this reason, in this post, we are going to review some of the little features we take for granted but that also make Varnish a great origin shield.