There is a disconnect in your messaging. Here on HN the title is "Learn what DDD, CQRS, and event-sourcing are all about", but the tagline in the PDF is "The semantic JavaScript backend for event-driven development".
So, what's this about? about DDD, CQRS and event-sourcing, or about a particular Javascript framework? Those two aren't the same at all (even though I suspect there is a little overlap).