YOE: 9
Been working at Google, since graduation in 2015. Currently, an L5.

Phone screen:
A few questions regarding the project that I was working on - first 15-20 mins.

Q1:⁠ ⁠https://leetcode.com/problems/subarray-sum-equals-k/
Given an array of non negative integers, return true if the subarray sum is equal to target.

Follow-up: What if we need to print the subarray ? How will you modify your algorithm ?
// [1, 3, 1, 4, 23], 8 -> true
// [1, 3, 1, 4, 23], 7 -> false

Q2: https://leetcode.com/problems/valid-word-abbreviation/
Check if the provided target string matches the internalization pattern string. You can assume that the strings are non empty.
// i18n
// m2a, meta -> true
// m2a, m!$a -> true
// m2a, messy -> false

I did well on this one. Interviewer's feedback was that I should've run through the code for Q2 with an example as I had skipped that one. Recruiter contacted me the next day and mentioned that we can proceed to the full loop.

Coding Round 1:
Q1: https://leetcode.com/discuss/interview-question/4288566/E4-meta-phone-screen-qs/
Q2: see question 2 from https://leetcode.com/discuss/interview-question/883800/facebook-phone-merge-sorted-arrays-merge-two-sorted-interval-lists

Solved Q1 very quickly. Got the algorithm correct for Q2, but missed an edge case while writing code and made my code more complicated than was necessary.
Interviewer's feedback was that Q2 could've been solved better. But, recruiter mentioned that this was okay.

Coding Round 2:
Q1: https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-tree-iii/
Q2: https://leetcode.com/problems/kth-largest-element-in-an-array/
Solved both Q1 and Q2 very quickly. Interviewer was nice.

System Design 1:
Design memcache on a single machine. The interviewer had the specs of the machine on which memcache would run (num CPU cores + RAM).
Interviewer was focussed on the following items: Data structure used for memcache, locking, and memory management.
https://www.educative.io/courses/grokking-the-principles-and-practices-of-advanced-system-design/single-server-level-of-memcache

I did alright on this one, needed hints for the memory management part. The interviewer's feedback was positive, and the interviewer was happy with the deep dives on the data structure (LRU - also discussed LFU) and the sharding of the HashTable into parts (approx. equivalent to the number of cores) to be able to lock more efficiently thereby increasing the throughput.

System Design 2:
https://www.hellointerview.com/learn/system-design/answer-keys/ad-click-aggregator
I had seen this question already, I was able to get through this one okay.

The interviewer's feedback was positive :)

Behavorial:
Q1: What’s your most impactful project ?
Q2: Tell me about a time where you had a conflict with someone in Management ?
Q3: Tell me about a difficult project that you worked on ?
Q4: Tell me about the best constructive feedback that you’ve received during your career and how did you address them ?

I was unstructured in this interview as I didn't really prepare for the interview. That's on me.
The interviewer's feedback was that I didn't demonstrate enough leadership and growing other people in my answers. Interviewer's recommendaion was "Hire as E5".

The recruiter reached out 2 days after the last interview and mentioned that the techincal part is very positive for both E5 and E6, but the beahvioral part was only good for E5. The hiring committee wanted me to go through another behavorial and I wanted to give it another shot.

Behavorial (Round 2):
Q1: Tell me about a time you volunteered to do a big project ?
Q2: Difficult working relationship that you've had ?
Q3: Tell me about a time where you didn't have enough data, how did you proceed ?
Q4: Tell me about a time when you picked up something from your peers ?

I thought I was more structured on this one and focussed on the leadership part. The interviewer's feedback was that there was enough data points to demonstrate leadership, but not enough to show that I "growing other people". Also, the interviewer felt that the difficult working relationship story I shared wasn't very good and I could've done acted more quickly in that situation. Therefore, the recommendation was, again, "Hire as E5".

Overall:
Recruiter contacted me 2 weeks after the last behavioral round and mentioned that they wanna move to team matching phase as E5.
Recruiter also mentioned that there were lots of discussions around the interview results and levelling as the technical side was strong for E6, but the behavioral side was found lacking for E6.

I appreciated the feedback, and politely declined as I believe my L6 promo at Google will go a lot faster than the move to Meta to start over as an E5.

Timeline:
It took about ~3 months from the time of the first phone screen to the follow-up behavorial round.

Retrospective:

• I probably should've prepared more for the behavioral (the first time around) as I left it as an after thought and spent more time on LC + System Design.
• I really did think that I did okay on the second behavioral, but I probably didn't highlight the data points that the interviewer was looking for in an E6.
• Also wanted to note that all the interviewers were really nice and professional.

PS: I'm not one for writing posts, but wanted to give something back to LC as I've only been leeching off of LC for the past 3-4 months :)