hypothetical Dockerfile:

    FROM python
    FROM nodejs
    RUN sh -c 'python ... | node ...'

Imagine this Dockerfile being valid. We want to express the idea of composing these two images into one and using binaries from both. Consider that those might have conflicting /usr/lib contents?! This is easy with flox+nix because that conflict doesn't happen.

There are other benefits such as: - minimal containers - automatic extraction of artifacts and their runtime-dependencies - no more pushing your compilers into prod - no cleaning steps (apt-cache clean) - declarative - reproducible - more fun!