TSP solver wins $100k prize at Amazon's “Last Mile” ML Challenge (using no ML)

The short papers accompanying the submissions are not out yet, but apparently the winning team did not use ML at all:

https://mobile.twitter.com/alexkontorovich/status/1423259110...

General introduction to the TSP problem video by a member of the winning team:

https://m.youtube.com/watch?v=vQMFVLa7yYQ