Why Your Docker Build Takes 11 Minutes in CI When It Takes 20 Seconds Locally

If your Docker build is fast locally and slow in CI, the base image is almost never the problem. CI runners are ephemeral, so they start with an empty layer cache unless you explicitly wire one up, and a COPY . .

Source: [Dev.to](https://dev.to/libme/why-your-docker-build-takes-11-minutes-in-ci-when-it-takes-20-seconds-locally-3foe)