If you've done a fair amount of leetcode problems you can recognize them and feel their levels. Then afterwards you can search and confirm your expectations.
It is not uncommon to have either verbatim or lightly modified leetcode problems as technical challenges for interviews. I think Facebook now makes it standard you need to be able to solve 2 leetcode medium questions in a 45 minute interview.
It was a difficult problem, and I was genuinely interested in the solution. So I searched online after the interview and found that leetcode called it a hard problem.
Wow, so that problem was from the LeetCode website itself?
Was it with different parameters or different phrasing, ... Or everything was the same?
If same but different, I wonder how (un)likely it is that they came up with that problem themselves, independently, without knowing about the LeetCode version. (What would you think?)
Or is it similar to LeetCode problems, although not actually on their website?
Does everyone remember all question titles by heart and that's why they say it was Leetcode questions, or is it more figuratively speaking :-)
I hope you'll find a place with an interview process that works for you.