What missing in this sentence about TTFB

A quote I like states: "Like all vain men, he had moments of unreasonable confidence.” ― Warren Eyster, The Goblins of Eros"

In that spirit I ask... Is the below sentence correct? What would you add, remove, reword or expand on?

In brief, some of the factors that can cause slow TTFB are: DNS latency, database, server side scripting, server hardware, poorly configured server, lack of caching and webhost network and upsteam performance.

Background: I'm writing a blog post and I want to be as throughout as possible and this sentence is part of the overview of TTFB.

Any help used here will be credited in the footer of that post.