Wrote a pretty comprehensive document on how to improve the performance of WordPress sites for the Sucuri blog.
I tried to cover the 3 core areas to make something go faster: reduce distances, do less things, go faster. And how that applies to WordPress.
Check it out here: https://blog.sucuri.net/2017/01/wordpress-performance-optimization-guide.html
*I have been writing quite a bit on the Sucuri blog, specially about malware research and web malware. Check it out there too.