[bergkvist]

The biggest limitation of using Docker for building images is that it does not allow for composition. You can't simply say you want to combine a Python and Rust image for example.

With dockerTools from nix (https://nix.dev/tutorials/building-and-running-docker-images), this kind of composition is easy. You also end up with significantly smaller image sizes - containing only exactly the dependencies needed for the image to work, which is also good from a security perspective - since it decreases the attack surface.