Author here:
Happy to answer questions.
I've been enjoying the journey of bringing Nix into the supabase community. There are some interesting challenges here, and we're already reaping some of the rewards. One of the most interesting and innovative things that has emerged has been to use nix to test upgrade/downgrade issues for postgres (as discussed in the blog post).
Nix has also made testing version of postgres, extensions etc in development far more streamlined, and I've spent time recently working with people internally to start to learn to leverage the ability to switch to any commit or branch, and build/run/test versions.
