I think this medium post by the author is the same text as the PDF.

https://medium.freecodecamp.org/the-complete-javascript-hand...

I find myself on flavio's site pretty often coming from google when looking up node topics. He puts out a lot of content, publishing every day. You also might be reading his node content as the official getting started guide on the nodejs website, pending this PR's review.

https://github.com/nodejs/website-redesign/pull/105