Nix Flakes and Private Repositories

NixOps also builds your stuff locally and copies it (probably with nix-copy-closure).

Building locally (which NixOps does and probably also deploy-rs) vs building remotely (which most other systems seem to do) is one main difference between deploying solutions. Did you know these two pages:

They list some different solutions.

NixOps can even set up your AWS resources.