Website performance can be a minefield, especially when trying to leverage things like WordPress and WordPress Plugins. It is almost enough to make one build things from scratch. Thankfully it hasn't gotten that far... yet. That said, here are some resources and thoughts on web hosting and performance.
Wither the NSA
USA hosting companies, regardless of website locations, are subject to FISA enjoinders. Therefore it is no longer acceptable to use USA hosting companies. This is the government really doing in an entire market. Wow, what a blunder. That said, my current favorites of Linode, Digital Ocean and even my beloved Servint are no longer viable.
Of course it may take a while to get situated, but a good place I will start testing is EDIS.AT.
Performance of Components of a Web Application
Performance starts with the network, hence hosting issues. And also is constrained by hardware, so things like bandwidth, throughput, and bus speeds along with ram and HDD vs. SSD drives.
And of course configuration of the entire web application stack including the application servers (PHP/Python/Ruby), database (mariadb/postgresql) and then we proceed to the web server (apache, etc.).
- ab Apache server benchmarking tool
Then the browser needs to be analyzed and the web application itself, along with other things such as compression.