eternal wishlist item for container builds: package manager integration. That means per-file caching for library downloads, out of order installation for when you change one thing in your dependency file.

(you can kind of make the caching happen with buildkit but it's annoying to set up)

I'm not sure any layer DAG tool will solve the packaging issue because dags are inherently ordered right?

cloud providers and users are probably aligned here in terms of goals: faster builds, smaller incremental deploys