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How we build sub-second Next.js sites

The performance principles behind every site we ship — and how to hit a 90+ Lighthouse score without sacrificing design.

Next.jsPerformanceEngineering

Speed is a feature. It affects conversion, SEO, and how premium your product feels. Here's how we consistently ship sites with sub-second Time to Interactive and 90+ Lighthouse scores.

Server-first by default

With the Next.js App Router, we render as much as possible on the server. Client JavaScript is reserved for genuine interactivity — a theme toggle, a form, a scroll animation — not for laying out static content.

Ship less JavaScript

  • Keep interactive islands small and specific.
  • Prefer CSS for motion and layout where it's enough.
  • Lazy-load anything below the fold that isn't critical.

Design tokens, not one-off styles

A small, consistent set of design tokens keeps the CSS lean and the UI coherent across light and dark themes. It also makes the whole system easier to maintain.

Measure, then keep it honest

Performance regresses quietly. We treat Core Web Vitals as a budget in CI, so a heavy dependency or an unoptimized image gets caught before it ships — not after.

Fast isn't an optimization pass at the end. It's a constraint you design around from the first commit.

Keep reading

Let's build something worth shipping.

Tell us about your project and get a free, no-obligation consultation. We reply within one business day.

+1 289-633-4230