I assume the author is reading the comments here and decided it would be in their best interest to make the repo private.

Amazon engineers [who are in a senior enough position to care] read HN too.

Does a GitHub archive exist? It sure is something to see code ebb and flow at the whims of the few.

Another reminder that you should always instantly download everything you ever find interesting or valuable. The internet is temporal because it's backed by people and infrastructure which are fallible and fragile in the face of law and talk.