Ask HN: Website Speed Optimization?

There was a discussion yesterday regarding minification, and as someone who's obsessed with optimizing for speed, i figured i should post this question that i have been pondering for a while. what are some innovative optimization strategies you have stumbled across, or/and use?

There is one that i saw on HN a few years ago, i tried to find it again but was unsuccessful, the gist was that they removed some non needed headers and saved a massive chunk of bw cost and gained speed.

I'll start, here's a few:

- enable gzip/brotli

- compress images

- minify css/js

- use of cdn

- link tag with appropriate rel, decoding, loading and fetchpriority attributes

- cache headers

- fetchpriority attribute on css, js, fonts and what not.

- order of js, css, and font loading in head tag

- use of defer attribute

- use of loading and decoding attributes on images

- get rid of 19 out of those 20 3rd part trackers every site seem to desperately need that defeat any or all of the other optimization attempts you are doing.