[rambleraptor]

Aside - where was the diagram made?

[yardshop]

Looks like something one could make pretty easily with Excalidraw (https://excalidraw.com/) although the font seems slightly different.

[Jtsummers]

Maybe not the case, but often that style was made using Excalidraw: https://excalidraw.com. Playing around in it, the font at least appears the same.

[yardshop]

Haha, I had the same thought about the program and the opposite conclusion about the font! Many characters like g and p look similar, but the lower case t has a curl on the bottom in Excalidraw, and is straight in the article's diagram.

Edit: on second look, it is the same t. I saw some images in a search for Excalidraw with a different t, but when I tried the actual site it was the same. Sorry for the noise!