Services
Slowness is not an opinion, it is a measurement. First we find where the seconds go, then we change what actually costs them.
The database first: slow queries, missing indexes, the searches that walk the whole catalogue. Then the front end - what the browser downloads, parses and executes before a person can click anything.
Core Web Vitals come from real visitors, not from a lab run on a fast laptop. So do the conclusions.
On a large catalogue the search is the first thing to stop scaling, and no index fixes it: at the worst point a search took eight seconds while the warehouse waited. Moving it out to Elasticsearch took that to one.
On the public side the answer is usually weight: a page that shows text should not ship half a megabyte of JavaScript written for a shop you do not run.
Numbers before and after, on your own system and your own data - not a promise of “up to three times faster”. Plus the list of what was changed and why, so the next person can read it.
And an honest line about what is not worth fixing: some of it is cheaper to live with than to rewrite.
Half an hour on a call: your screen, your real system, an honest answer about whether the task is mine.