It's a little more on the nose. I just checked the subforum for a random quant firm and it goes something like:

* Just interviewed at {firm}, here are the questions:

1. Question One: here are the math and stats subquestions.

2. Question Two: here is the Leetcode question they asked.

3. Question Three: here is another question and my solution.

4. ...

Followed by other users posting stuff like "Thank you Landlord {OP}" or "Giving rice {forum clout points} to this Landlord {OP}." Guests without accounts are tourists. I'd say it's like the Leetcode discussion forums except they're leaking actual company interview questions.