Oracle On-site interview

Can anybody share his/her experience of Oracle on-site interview. How to prepare for that strategically and how do they evaluate a candidate (perfect solution or what)?. My strategy for preparation is:- Leetcode - ~50-70(hard), medium(~200), revise OS concepts, designing of distributed systems. If anybody can suggest me anything on this then it would be very helpful. P.S:- I have been preparing medium and hard questions of leetcode, almost 150 are done and some extra/variations from geeks.