This was a fun read for really personal reasons. The idea that, basically, bad code no one ever has to touch again is in fact good code, is in fact "better" in a true sense than carefully engineered code accomplishing the same thing, has been a really valuable guiding insight for me in my career. I couldn't remember where I got it though, or if it even had one single source.

Then when he shows the visualization I was like "hey that looks like the d3 script I got out of some git analysis book years ago and still use at every job I work."

It's the same guy! Looks like he productized the scripts distributed with that book, which nice. I'll definitely try it and push for places I work to pay for that instead of the bundle of customized scripts I've been dragging around for years.

I really endorse that book too! I read it at the right time in my career I think, where I had truly seen some shit and so had the experience to understand the value of that approach, but not so far in that I had become set in my ways.

So there is a script or something with the book that you can run on your Git repo to see a chart of the hotspots?

Then visualize it however. I have some d3 scripts that came with the book that I've modified and you can track down somewhere on github I'm pretty sure. I mostly use those for demoing it to devs unfamiliar with the techniques though, since it looks cool and is immediately obvious what it's for.

For serious use I dump it into sqlite and use a mix of different scripts and techniques to figure it out. It's been kind of a language playground for me over the years so is in a lot of different languages and is "learning code" in most of them. Cleaning them up and sharing is one of those "maybe some day" things though.