Next.js Bundle & Build-Time Optimizer

Data-driven optimization loop for Next.js 16 applications. The skill orchestrates next experimental-analyze, builds, type checks, and tests to make verifiable improvements one change at a time.

When to Apply

Use this skill when:

• The user wants to reduce bundle size / First Load JS / route bundles in a Next.js 16 app.
• Production builds are slow and the user wants to diagnose and fix the bottleneck.
• The user shares analyzer output, a screenshot of the treemap, or asks "why is <X> so big?"
• A new dependency was added and bundles grew — they want to understand why and unwind it.
• The user wants to set a performance budget and enforce it iteratively.

Why iterative (not "apply all optimizations at once")

Bundle optimization is full of foot-guns. Examples:

• Moving a "client-only" dep behind next/dynamic can break SSR consumers that depended on its presence at first paint.
• experimental.optimizePackageImports with the wrong package can mis-resolve subpath exports.
• Aggressive modularizeImports regex rewrites can hit unintended modules.
• Narrowing the polyfill target can break older mobile browsers in production.