Slow websites lose Indian mobile users fast — most of our traffic comes in on 4G, not fibre broadband, so performance isn't optional. Here's the checklist we run through on every Next.js build before launch.

First, images: use next/image everywhere, serve WebP/AVIF, and set explicit width/height so the browser doesn't reflow content while loading. This alone fixes most Core Web Vitals complaints we see in client audits.

Second, rendering strategy: static generation (SSG) for marketing pages and blog content, server-side rendering only where data changes per-request, and client-side fetching reserved for things behind a login. Mixing these up is the single biggest cause of slow Time to First Byte we find in legacy projects.

Third, bundle size: audit your dependencies quarterly. It's common to find a full date-picker library imported for one form field, or a charting library loaded on pages that don't use charts. Code-splitting and dynamic imports handle most of this automatically once you're aware of it.

Finally, we always test on a throttled 4G connection, not fibre wifi — because that's how most of our end users will actually experience the site.