You run close to the metal, eh? Then you might find this project interesting to hack on:

http://nerves-project.org/

FWIW, the class for it was the first class to sell out for the upcoming https://elixirconf.com/.

Here's a great presentation by Garth Hitchens on Nerves https://www.youtube.com/watch?v=O39ipRsXv3Y (he uses it in production at his company, http://www.rosepoint.com/, which builds sort of vertical-market marine navigation hardware). He mentions some performance stats as well.