Did you also skim the accompanying (or rather, main) repo, https://github.com/twitter/the-algorithm ?

From a quick clone and line-count, it has:

  235 kLOC .scala
  136 kLOC .java
  22  kLOC .py
  7   kLOC .rs

So I don't think you did, since you posted so quickly and that's a LOT of code.

I also haven't skimmed this code except very superficially, but perhaps you should since you're out there making statements with your Princeton credentials.

(I posted this comment with the heads-up a few minutes after your comment above and then expanded it as you didn't respond.)