Technical Blog Post for Developer Audience

# How We Cut Our Next.js Build Time from 12 Minutes to 90 Seconds

**TL;DR:** Our Next.js app's build time grew to 12 minutes as we hit 800+ pages. We fixed it by switching from `getStaticProps` to ISR, parallelizing image optimization, and moving to Turborepo. Build time: 12 min → 90 seconds. Here's exactly how.

The Problem

At Flowdesk, our marketing site has 800+ pages (blog, docs, changelogs, landing pages). Every deploy meant a 12-minute wait. Engineers started batching changes to avoid the build, which meant bugs shipped in larger, riskier chunks.

The Fix (3 Changes)

1. Incremental Static Regeneration

// Before: every page built at deploy time

export async function getStaticProps() {

const posts = await getAllPosts(); // 800+ API calls at build

return { props: { posts } };

}

// After: only build the top 50, regenerate the rest on-demand

export async function getStaticPaths() {

const topPosts = await getTopPosts(50);

return {

paths: topPosts.map(p => ({ params: { slug: p.slug } })),

fallback: 'blocking', // generate others on first request

};

}

export async function getStaticProps({ params }) {

const post = await getPost(params.slug);

return {

props: { post },

revalidate: 3600, // re-generate every hour

};

}

**Impact:** Build went from 800 pages → 50 pages. Time saved: ~8 minutes.

Gotcha

The `fallback: 'blocking'` option means the first visitor to an un-built page waits for generation. For us, that's fine — these are long-tail pages with <10 visits/day. If your tail pages get traffic, use `fallback: true` with a loading skeleton instead.