Optimize your Dockerfile for 5x faster builds

Slow Docker builds are annoying. You make a small code change, run docker build, and wait. This post shows you how to optimize your Dockerfile for faster builds. These Dockerfile optimization techniques will work whether you're building locally or in CI, and for any language. The examples in this post use a Node.js application with about 40 dependencies (including common packages like ORMs, UI libraries, and AWS SDKs) to represent a production React/Node application.