Had the oppotunity to interview with google,thought to share the same with the community that helped me.
[Won't Reveal the exact question but will give a fair IDEA].

Phone Screen:It was on HashMap [You could solve it if you know https://leetcode.com/problems/longest-consecutive-sequence/] This Round went superb,was able to code fast ,asked right question and implement it.

Got a green light from recruiter after a week.Had my onsites[3+1] after a week[In India they are doing a GCP specific hiring where they have 3 tech rounds and 1 G&L round]

Round 1:Interviewer was a Competetive programmer(He told me upfront),asked about a question on range queries
Told different approaches but he was looking for SEGMENT TREE.I was not confident in it but coded it anyway but took a lot of time.Also was unsure of my code.[No time was left to test and follow up].

Round 2:Interviewer was super nice,asked a question that was Math problem more than algorithm problem,he was looking for approach and questions asked,He was looking for specific Formula which i don't think anybody can think of[I still don't get that formula].After a hint he basically fed me that,I coded it up.Follow Up was what all test cases you would write.

Round 3:Interviewer was nice,asked a problem which was basically NP complete+GRAPH problem,hasn't seen anything like that while preparing.I got to certain point coded the problem got confused with BFS and changed strategies midway to DFS,but I missed a crucial line[1 line only] of code which i noticed after the interview[Everything else was spot on which I later verified].Follow Up was about updates in values which i couldn't think of in limited time.

Round 4: Nothing fancy here but just a casual conversations about goals,past failures and different generic behavioral questions.

After some days got an Update about reject from recruiter Saying that feedback for 2 technical rounds was not good,1 was positive and they have decided to move with other candidates.

NOTE:What i have learned is that interviewing at Google(or any company) is more of luck+skill based game,I got three super weird and hard questions which I was not ready/prepared for whereas some guys gets asked Simple BFS/DFS or simple DP based questions.

TBH I am feeling a bit down at the moment that my preparation hasn't helped me[SOLVED 300+ LC questions] because i didn't brush up on ADVANCED DS/ALGO, but you can't change things which are out of your control and there is plenty of fish in the SEA,so hoping for the best in other companies.

If you guys can share your views that would be great