I interviewed for the Google Early Career Software Engineer position for the US and unfortunately I was rejected despite doing good in most of the 5 rounds:

First round:
Behavorial round and fel that I answered clearly and logically to all his basic project and behavorial questions.

Second round:
The question was basically a heap question where you have a class and you need to always keep track of the k smallest elements through multiple functions that were given.
I felt I did really good this round but there was something here and there I could improve on.

Third Round:
The question was a tree question where you need to remove the nodes of a tree starting from the leaves. The follow up question was if a leaf is removed, then the parent becomes a new leaf, then the new leaf must be removed before all other nodes.

I used post order traversal to solve this. Felt really good about it, the follow up question was a bit tricky but I believe I did well on it as well.

Fourth Round:
This was the hardest for me. It was some weird question about an array of treenodes and that I would have to traverse through this array of treenodes in order to delete the designated one and all of it's children.

The interviewer was very bad at explaining the question and didn't want to be there. If the interviewer was better, I think I could've done much better.

Fifth Round:
This was my best round. The question involved arrays and a use of a hashmap, specifically a Counter (in Python). I managed to answer the question and it's follow-up optimally with time to spare and the interviewer himself looked impressed.

After I finished all 5 rounds, I felt pretty good for 4/5 rounds but the 4th round could possibly screw me over. Then after a week and a bit of waiting, I got an email saying I wasn't chosen and I'm still waiting to schedule a time to receive feedback from my recruiter for why I wasn't chosen.

Tbh, I'm frankly dissapointed, I binged leetcode for months and have done hundreds of questions on here. But at the end of the day, it is Google's loss and I'll just have to be patient and keep grinding. :)