You using HTTP in the example without explaining it, was really funny. Was that joke on purpose?
When you write anything, you have to assume your audience is at some baseline of understanding the topic. Otherwise, every software article would have to begin by explaining what a computer is.
In an article about optimizing web performance, it seems like a reasonable assumption that the reader would would already understand what "HTTP" means even if they don't recognize the abbreviation "TTFB."