A good Dockerfile does more than make a build succeed; it improves CI time, image security and production readiness.
1. Start from a better base image
Choosing a smaller and more appropriate base image affects size, security and pull time immediately. Use the image that matches your real runtime instead of the most familiar one.
2. Design cache behavior deliberately
The order of COPY and RUN instructions matters. Files that change less often should come earlier so build cache stays effective in CI and local development.
3. Separate the build image from the release image
With multi-stage builds, you can keep build tooling in one stage and produce a smaller, safer and cleaner production image in the final stage.