Almost every performance engagement starts the same way: someone ran PageSpeed Insights, got a red score, and started applying the suggestions from top to bottom. That rarely works, because the tool lists symptoms in the order it found them, not in order of impact. I profile first — real user data from Search Console and field metrics, then traces — and fix the two or three things actually holding your numbers down. Usually it is render-blocking resources, an unoptimized hero image, or a hydration cost nobody measured.
A Lighthouse run on your laptop over fibre tells you very little about a user on a mid-range Android phone. Core Web Vitals are assessed on field data, so that is where I start — Search Console's Core Web Vitals report and CrUX, segmented by device. Lab tools are for diagnosing causes once the field data has told us where to look.
Performance work has severe diminishing returns, whether the site is WordPress or a Next.js application. Two or three fixes usually account for most of the available gain, and the remaining forty audit items account for very little. I would rather hand you a short list with measured impact than a long one that keeps you busy without moving the numbers.
Sites regress, because someone adds a tag manager container or a hero video and nobody notices until the next audit. I set up budgets and monitoring so a regression shows up in CI or in your dashboard rather than in a ranking drop three months later.
It depends entirely on what is wrong. Sites that have never been optimized frequently see LCP halve, because the cause is one oversized image or a render-blocking script. Sites that already had attention paid get smaller gains. I will tell you after the audit, before you commit to the work.
They are a ranking signal, but a modest one — relevance beats speed. The stronger argument is conversion: slow pages lose users before they see your content. I would not sell performance work purely as an SEO play.
Both. WordPress performance work looks different — plugin bloat, unoptimized queries, theme scripts loading everywhere — but the method is the same: measure, find the real cause, fix that.