Distributed Systems and ML are probably two most interesting things that I have on the radar, that got me really scared to the point where I do not know from where to start, and most importantly for what?! Most of my free time (time I spent on personal projects) was writing physics simulation in Java, playing with Lisp and doing some backend development. Nothing amazing. Year and a half ago I got really interested into Operating systems (tried FreeBSD and blew my mind) and played with Docker. And at the end of this year, I am like: "Ok Philip what shall I focus on for year to come?" And the thing is If I choose to go Ai route, I do not know from where to start (I consider my math background to be pretty good, I was studying EE before I dropped out after 2 years, and enrolled to CS, done all of the math courses which were pretty rough), Ai/ML looks interesting but it looks so high level to program and so abstract to understand. It's really looking like arcane magic to me. With Dist. Systems is that I have a feeling that is more "engineering" and "industrial" thing, where you can't do much by yourself at home, besides reading and writing some code in relevant languages about backend, sometimes lower level, and learning about systems and computer innards. And the third option was to go and play with Erlang/Elixir, which is most attractive since results will come pretty soon, and may be relevant form my interest in Distributed systems.