I want to look into apt-cacher-ng for learning purposes, to stop 10s of VMs in my homelab from adding load to Debian official repos, and also to check if there is a way to have it only mirror a list of “approved” packages.
saw a huge time improvement even though I have a good internet connection
Note that for best performance you should use deb.debian.org
Semi-related I have set up a personal APT repository on gitlab pages: nodiscc.gitlab.io/toolbox/ (I think Ubuntu users would call that a “PPA”). It uses aptly and a homegrown Makefile/Gitlab CI-based build system (sources/build tools are linked from the page). I wouldn’t recommend this exact setup for critical production needs, but it works.