Solved: Cut my next.js (docker) build time by 2/3’s switching from pnpm to bun

🚀 Executive Summary TL;DR: Next.js Docker builds often suffer from slow dependency installation due to improper Docker layer caching, particularly with pnpm. Optimizing Dockerfiles through multi-stage builds, or a quick switch to Bun, can drastically reduce build times by up to 66% by preserving cached dependency layers. This prevents unnecessary re-installation of packages on every code change, saving CI/CD costs and developer time. 🎯 Key Takeaways Naive Dockerfiles invalidate cache layers by copying the entire project context ( COPY . . ) before dependency installation, forcing repeated pnpm install runs even for minor code changes. Switching to Bun can provide an immediate, significant reduction in Next.js Docker build times due to its inherent speed and potentially less sensitive caching behavior compared to a poorly configured pnpm setup. Multi-stage Docker builds are the recommended, package-manager agnostic solution, separating package.json and lock file copying from application