There is some decent material here, but contrary to all the posts saying "great article", I would like to sound a note of caution. There are also quite a few half-truths, implicit assumptions and significant omissions in this article, and I would advise anyone who isn't already familiar with the field to seek out other material that is more comprehensive as well.

I hate it when people criticise without giving specifics, so here are some of the more obvious examples:

- The article mentions image sprites, complete with the trendy but semantically dubious hijacking of the <i> element for icons, but does not discuss data: URLs.

- The article talks about the performance implications using subdomains, but doesn't mention anything about cookies.

- The article makes many assumptions about how assets are loaded that may be true in the major browsers right now but tend to change very fast, and even then it doesn't mention that there are actual standards for how browsers are supposed to behave in this respect (which in turn not all browsers follow).

- The article promotes techniques that will achieve lower quality results, such as serving low-res assets to high-res devices and using CSS approximations of effects to avoid using image files at all, without considering techniques for serving some but not all assets depending on the nature of the requesting device. Crucially, there is also no hard data at all about what the relative costs actually are and therefore whether these implied optimisations are actually giving worthwhile savings.

In short, this article is a decent thought-provoker if you're new to front-end development and aren't necessarily aware of these kinds of issues, but it's not comprehensive (and there are other resources that are) and it does advocate some questionable practices.