Julia's now using Ipad with pencil and the Notability app. She previously used a Samsung Chromebook Plus with Squid.

She actually wrote a blog post about reverse engineering the file formats when transitioning between them: https://jvns.ca/blog/2018/03/31/reverse-engineering-notabili...

(btw, if you go through her drawings over the years, they got better and better. I think a lot of what makes them great nowadays is practice, practice, practice)