I just watched the entire video and it was very informative. Fwiw most of the comments on here did not watch the video and seem a little uninformed. The node apis were built by a small group of front end developers and most of the pulled out services they're building are in python .

There were also a lot about message queues, cacheing, and ops related things in the talk.

I definitely recommend watching the entire video if you're interested in high traffic architectures.