Site speed is not a launch-day property; it is a habit. Every slow site was fast once, three hundred content edits ago. This checklist is how you keep the habit.
A theme can only set the stage; content keeps pages fast or makes them slow. Here is the short checklist we apply to every Peerless page.
None of these require a developer. All of them show up in your Core Web Vitals.
Run PageSpeed Insights on your two highest-traffic pages once a month. If a score drops, the cause is almost always in this checklist — usually an image. The theme handles the rest: modules load their CSS and JS only on pages that use them, and layout work is moving to container queries so responsive behavior costs nothing extra.