How our Lighthouse scores cleared 90+ after migrating to the new router. The full production checklist.
Metadata API
Dynamic OG images, canonical, i18n alternates inside generateMetadata. Without them, social shares fall flat under App Router.
Smart caching
Separate fetch revalidate from route dynamic behavior. Static + ISR covers most cases; route segment config is your friend for semi-dynamic.
Image optimization
next/image with sharp practically zeroes CLS. For maskable assets like a logo, CSS mask + one PNG removes the need for three separate SVGs.
