Learn how to generate Atom/XML feeds based on tags by using Middleman.
How to find a compromise between quick and crappy vs. slow and perfect.
Learn how to take a snapshot and animate it as GIF, each time an app error occurs.
It took 3.5 years of work, but on September 2014 the Elixir team released version 1.0.0. This is why we are so excited about it!