It's the word I use for exploring unfamiliar (and potentially scary) parts of a codebase

I take it you don’t play video games either. Spelunky was a pretty popular Indy game back in the day. Named after, you guessed it, spelunking. I first learned the word from “Where in the world is Carmen Sandiego” back in the 90s. I had to ask my parents what it meant.

There's also an old NES game called Spelunker.

This comic is my first memory of the word https://www.gocomics.com/calvinandhobbes/1986/08/07

Yes but my experience with WITWICS predates the NES for me.

First time I heard it in English! Your comment made me want to dig deeper... It looks like it comes from the Latin "spelunca", meaning "cave"

Curiously, in Portuguese we have "espelunca" which is more commonly used as a synonym for a seedy, shady place -- and now I know why!

in german "Spelunke" is used for a seedy, shady bar

And another fun bit of trivia: in the animated series “The Seven Deadly Sins”, one of the characters owns and operates a somewhat suspicious bar in a remote mountain cave.

Seems there may be a cross-culture notion of caves and sketchy bars having similar level of… ah, “shadiness”. Makes some sense, as I’m typing this out. The dark is where (both literally and figuratively) shady things go down, and it’s hard to get much darker than a cave, so “Spelunke” seems a fitting name.

Same case for "spelunka" in polish

Have you heard of the Baader–Meinhof phenomenon?

https://en.m.wikipedia.org/wiki/Frequency_illusion

No, but now I'm seeing it everywhere!