I am in the interview process with many different companies and made to onsite with most. The interesting thing is that I have yet to encountered the "Hard" level questions with any one of them. Not from Google(on-site pending), Facebook, Amazon, etc... The questions were all either very similar to easy-medium questions or slight variation.

Am I just extremely lucky? or have other people had similar experience? I started working on Leetcode about a month ago and can solve most medium problems without looking at the discussions board, but the hard ones are still.... hard for me.

So, if I have an interview in 3 days with Google, should I focus on reviewing fundamentals and absolutely nail down easy-medium questions or should I try to cover as many hard questions as possible, so I will at least have some high-level ideas for similar types of problems?