I think the audience is more the quantitative "data science"/ machine learning crowd. The nice friendly web design makes this look deceptively simple (and it i

I think the audience is more the quantitative "data science"/ machine learning crowd. The nice friendly web design makes this look deceptively simple (and it is if you have the right background), but this type of material is not aimed at a general audience. At the same time, as noted by another commenter, this isn't arXiv material either. It's somewhere in between.