Core Web Vitals are the rare metric set that measures what users feel and what Google ranks. After taking a string of client sites from failing to green, the pattern is clear: most slow sites share the same four or five problems, and none of them are exotic.
LCP: your hero is the problem
Largest Contentful Paint is usually decided by one element — the hero image or headline block. The fixes that move it: serve the hero as a properly sized, modern-format image with priority loading; render the page statically or from the edge so HTML arrives fast; and stop hiding the headline behind a web font that loads late. Font-display swap and self-hosted fonts routinely cut half a second on their own.
INP: death by hydration
Interaction to Next Paint punishes sites that ship megabytes of JavaScript to render what is, functionally, a document. The cure is architectural: server components by default, client JavaScript only where there's genuine interactivity, and third-party scripts loaded after the page is usable — or evicted entirely. We've seen tag managers cost more milliseconds than the entire application code.
CLS: reserve the space
Cumulative Layout Shift is the easiest of the three: give every image and embed explicit dimensions, reserve space for anything that loads late (ads, banners, consent bars), and never inject content above what the user is already reading.
Making it stick
The teams that stay green treat performance as a budget, not a project: per-template thresholds wired into CI, so a regression fails the build instead of reaching customers. One client's storefront has stayed green for a year that way — through dozens of releases and a Black Friday.
Green vitals won't rank a site with thin content. But between two comparable pages, the faster one wins — and your users feel the difference long before the rankings show it.