How I Shrunk Our Docker Images from 1.2GB to 85MB Using Multi-Stage Builds

Last month, a junior dev on my team pushed a Docker image to our registry. The CI pipeline sat there for 11 minutes. When I checked, the image was 1.2 GB. For a Python web app with 3 dependencies.

I've been there. You probably have too. The apt-get install creep. The forgotten pip install cache. The "I'll clean it up later" that never happens.

Here's how I fixed it — and how you can too.

The Problem With Fat Images