Scores are symptoms, not the diagnosis
Lighthouse is a lab snapshot; field data in Search Console reflects real users, devices, and networks. Prioritise templates that carry revenue or leads.
Largest Contentful Paint (LCP)
Optimise hero media, server response time, and render-blocking assets. Preload critical fonts and images above the fold; lazy-load the rest.
Interaction to Next Paint (INP)
Heavy JavaScript bundles and main-thread work delay clicks and form interactions. Split bundles, defer non-critical JS, and audit third-party tags quarterly.
Cumulative Layout Shift (CLS)
Reserve space for ads, embeds, and dynamic widgets. Avoid inserting banners above loaded content without reserved height.
Operational ownership
Assign owners for tag management, CDN caching, and image pipelines. Performance regressions usually return when nobody owns the budget for bytes.