In our work, we outlined persuasive arguments why website loading speed matters from visitors' perspective. Before diving into specific solutions, we discussed general techniques for WordPress-based website performance optimizations to give the reader a technological overview. We then proceed to carry out detailed comparisons between different server stacks, such as Apache with mod_php, Nginx with PHP-FPM or HHVM, pointing out both their advantages and disadvantages. Along the way, we have created a powerful yet simple framework for performing the comparisons on any Ubuntu-powered machine, allowing the reader to follow the work more closely at his or her own conditions.
Furthermore, we talked briefly about three main layers of caching (database, page and browser) as well as in which circumstances they could be employed. We have seen how to profile a WordPress website completely with its plugins and themes. Last but not least, we gave the reader an introduction into writing a more optimized PHP source code.
It is our firm belief that we have provided enough valuable information for the reader, introducing him or her into the fascinating world of the performance optimizations of websites build on top of the WordPress platform. Finally, we recommend going through the work's references as they depict the discussed topics in a greater depth.