Thanks so much! Let me think. Cloudfront, heavy NGINX caching, precompiling JS assets, using Go as a backend language, doing as few requests as humanly possible and lots of hard work. No silver bullets unfortunately, but some smaller nice tricks like using Thumbor as a Cloudfront custom origin. We'll definitely share some stuff on our engineering blog soon!
as someone who has worked on really large angular apps (and also someone who knows a bunch of the ng core guys) the load time on this is terrific and was pretty surprised by how quickly ng-repeat rendered. did you have to do anything special (i could probably poke around the code more but i thought asking might give me more insight)?