I gave an almost 2 hour talk yesterday about what Nix is (and why one would want to learn it), followed up by more of a workshop-style demo of how to use it, building up from the basics of the Nix language to more complex usages: Nix — не только пакетный менеджер - YouTube
Some people gave me feedback about it being quite useful already, so I thought I’d post it here. The talk is in Russian.