Every story and comment from the Hacker News API, in a layout borrowed from 2001.
A comment on Twitter open sourced the recommendation engine. Parent comment
From a quick clone and line-count, it has:
235 kLOC .scala 136 kLOC .java 22 kLOC .py 7 kLOC .rs
From a quick clone and line-count, it has:
(I haven't skimmed this code.)