Chapter 7. Optimizing for High Performance

Throughout the years, PHP has grown into a remarkable language we use to build our web applications. An impressive number of language features, alongside countless libraries and frameworks, make our job ever so easier. We often write code which encompasses several layers of stack without giving it a second thought. This makes it easy to overlook one of the most important aspects of every application--performance.

While there are several aspects to performance that developers need to pay attention to, the end user is only interested in one - the time it takes for their web page to be loaded. This is really all that it comes down to. Nowadays, users expect their pages to load in less than 2 seconds. Anything more and we face decreased conversion, which often translates into serious financial loss when it comes to big e-commerce retailers:

"A 1 second delay in page response can result in a 7% reduction in conversions." "If an e-commerce site is making...