Meta interview experience | L4 | Multiple Locations

I gave interview at Meta for L4 and here is my complete expreience.

Background: 3 YOE and Master's in CS

Applied via referral.

Mock interview:

1. Move 0 elements to end (Struggled a bit and came up with the solution finally)
2. Maximum number of islands (Came up with DFS solution)

Feedback:

1. When interviewer gave me hint for the first question, I couldn't understand it. So I just ignored the hint and solved the question. She told me to listen carefully.

2. I did a dry run for the code using input she gave. She told me to take an new example (Better if it's an edge case) and explain

Screening Round:

1. Right side view and Left side view of binary tree
2. LRU cache

I don't think I have made any mistake here. She told that I did well in the interview. Got a reply 3 days after my interview.

Onside Coding round 1:

1. Maximum sum of the subtree in binary tree
2. Evaluate a string having only + and * --> 5*10+3 = 53

For first question I made a small mistake of not considering a case where the result could be -ve. I fixed after interviewer telling me.
No mistakes made on 2nd question

Onside Coding round 2:

1. Get all the subsets in a given subset --> {A,B,C} --> [{},{A},{B},{C},{A,B},{A,B,C},{B,C}]
2. Valid word abbreviation

First question I solved it but when explaining I thought I made a mistake, but interview said my code is correct. I realized that and completed my explanation.
I made mistake with picking wrong variable names. Corrected it after interviewer telling me.

For all questions I was able to solve them completly with optimal solution.

Behavioral Interview:
General behavioral questions that you expect.

1. Challenges in a project
2. Strengths, weaknesses
3. Conflict with manager
4. How do you handle deadlines
5. How did you handle receving feedback.
6. Did you take any initiative

For me interview went only for 25 mins. Interviewer before starting the interview said it wouldn't take whole 45 mins.
After 25 mins, I had some discussion with him for 10 mins and then parted.
I would say it went really well.

System Design:
Desing ad aggregation system.

This round went well.

My preparation:

Coding:
Solved top 100 fb tagged leetcode questions.

Behavioral:
Used chatGPT to give questions and answers. Changed them according to my experience. I prepared for around 10 hrs split across 3 days. I had my friend verify my answers and discuss, it helped a lot.

System Design:

1. System design Vol 1 and Vol 2.

2. First few chapters from Designing Data Intensive Applications.

I couldn't make it. Recruiter said there were no red flags but I haven't reached the expectations of L4.

It was devastating after hearing the results. There is cool down of 1 year.