Most slow sites are not slow everywhere. They are slow in one or two places that poison everything else, and the fastest wins come from finding those places before changing anything. This is the order I work through on every performance audit.
Start with the network, not the code
I load the site with caching disabled and read the waterfall first. Nine times out of ten the story is obvious: a hero video fighting the stylesheet, a chat widget loading before the content, or thirty tracking scripts each adding their own delay. Fixing delivery order beats rewriting components almost every time.
Then weigh the images honestly
After delivery comes weight. I list every image over a sensible budget and check whether it is served at the size it is displayed at. Oversized banners and uncompressed uploads are the most common finding in my audits, and also the cheapest to fix with responsive images and modern formats.
