If nothing else, check out the section starting around 45:55. He creates multiple nodes, connects them, deploys a function across them, and then updates the code everywhere without rebooting. The whole video is interesting, but that was a highlight.
Here’s an interesting walkthrough on using Elixir/Erlang to solve a real problem with resizing 2.7 million images. In Ruby, the image resizing was taking about 1 second per image. Rewriting it in Elixir/Erlang brought that down to 0.128 seconds per image.