Experience: 8 years
LeetCode stats: ~210 (30% easy, 60% medium, 10% hard)
Prep time: 2 months

Note: I am not giving any details/hints about the problems, because 1) I signed NDA 2) I realized they are not helpful and can only distract others preparing for interviews. The questions I was asked are not same as those mentioned in others interview experience.

Recruiter reached out through email. I asked for time before scheduling interviews.

Phone interview:
2 LP and LC Hard on Graph: Answered LP questions with details. Coded semi-optimal solution and later discussed the optimal solution.

Virtual Onsite:
Round 1:
2 LP and LC medium on Graph: Interviewer was very friendly. He asked many follow up questions on LP and it went on for 30 mins. I provided an optimal solution and discussed edge cases. This round went well and I could sense that interviewer was happy with my performance. I had 10 mins to ask questions. We had a very good conversation in the last 10 mins.
Round 2:
2 LP and System Design: Interviewer was very friendly. He asked many follow up questions on LP and it went on for 30 mins. System design question was fairly simple. I wrote down my approach. Interviewer asked questions in between that were more focused on functional features (rather than design) and I answered all of them. This round went well and I felt that interviewer was happy with my performance. I got a chance to ask questions in last 5 mins.
Round 3:
2 LP and LC medium on Strings: (Bar raiser) LP went well and interviewer asked follow up questions. It took close to 25 mins. I was given a sample input and output for the problem. I gave a brute force solution that worked for the given input. I wanted to then focus on providing optimal solution. But interviewer gave another input and expected output, which basically added another criteria that made the problem more complex and I was only able to complete a brute force solution that works for new input by the end of the interview. At the end I had 5 mins to ask questions.
Round 4:
2 LP and problem is not on LC: LP went well and interviewer asked few follow-up questions. Interviewer was busy typing as I talk. LP took 20 mins. I gave a brute force solution right away for the coding problem. I was unable to come up with optimal solution despite taking hints from interviewer. I had 5 mins at the end to ask questions.

Recruiter reached out after 2 days that they are not moving forward. It really hurts that I couldn't make it despite 2 months of hard work, but again there are people who spent years preparing to land a job at these top companies. It takes more preparation.

Resources:

1. LeetCode premium
2. G R O K K I N G the system design course and system design primer on GitHub
3. P-R-A-M-P for mock interviews

Lessons:

1. Learning more patterns is important than solving many problems of same pattern.
2. If you are applying for SDE2 and above, brute force approach will not guarantee the job.
3. Take a step back and think about a different approach even if you are in the middle of coding a non-optimal solution.
4. Learn to be patient and focused for 5 hours as the interview typically takes about 4 to 5 hours.

I hope my experience helps a few preparing for interviews. Good luck.