[evfanknitram]

I don't know what this means.

How is "single repo" a "design" and how does this design dictate dependency management?

Yes, if you have a single repo then that would be a single source of data for building your stuff. That seems redundant.

[justicezyx]

See Bazel, you have the depes manifested as source controlled the data, then you can build everything as deterministically as possible.

Then you can manage dependency as part of the normal source control process.