As in, the same very same tests your company now expects new candidates to "solve" (pretending they haven't seen it before) in about 30 minutes tops. In order to, you know, keep out the riff-raff.
I've solved almost all of the easy and mediums, though.
My perspective of "hard" LC problems is that they are typically distributed over a system anyways, where the optimal parts make the whole. That, or they are domain-specific analogs, like complex solvers, or involve graduate graph theory, etc.
What is your perception? I haven't done LC in about a year and a half.
There was maybe one question that I'd say was objectively hard (because it was completely unexpected and blew my mind - fortunately I did it OK) - but I don't think practicing LeetCode hard level would've helped there anyway. And then several questions were barely above LeetCode easy level and I had a brain fart. (Should have practiced binary trees a bit more, dammit.)
IMHO LeetCode hard level is a waste of time, unless you know for sure that the company you're preparing for gives these questions.
https://www.teamblind.com/post/I-always-ask-leetcode-hard-7S...
Smells like a troll - but perhaps only "partially" so.