Meta Interview Experience E4 | Infra | Pass | USA

I never thought I would be sharing this, but after passing my Meta E4 On-Site interview for an Infra role, I wanted to give back to the LeetCode community.

Phonescreen

• For the first coding question, I was asked to solve Valid Palindrome 2.
• The second question was Diameter of Binary Tree.

There was an additional question, 1249. Minimum Remove to Make Valid Parentheses, where only the thought process was required, not the code.

Behavioral Interview I

This round covered standard behavioral questions:

• Discussing a project I was most proud of.
• Describing a conflict with a co-worker and its resolution.
• Sharing feedback I had received and how I acted upon it.

System Design I

The core problem was to design a photo messaging app. The interviewer probed deep with follow-up questions:

• Why I chose SQL over NoSQL.
• What consistent hashing is.
• How to scale the system.
• Capacity estimates for the system.
• Explaining the upload and download process for photos/videos to/from S3.

I honestly felt I had bombed this round. The interviewer was very directive, asking deep-dive questions even before I finished the High-Level Design (HLD). Estimations were a specific focus.

Coding Interview I

• Question 1: 50. Pow(x, n). I initially provided an O(N) approach and coded it. The interviewer then pushed for an O(logN) solution. I fumbled a bit and needed some hints but eventually arrived at the recursive O(logN) approach.
• Question 2: Vertical Order Traversal of a Binary Tree. This was more of a discussion round. I had to explain why BFS is often preferred, why not DFS, and how to implement it with DFS. No code was required, and I answered all questions successfully.

Coding Interview II

• Question 1: A variant of 560. Subarray Sum Equals K, asking to return true or false if such a subarray exists. I was also asked to optimize for space/time complexity.
• Question 2: Antidiagonal of a matrix. This round went smoothly with no hiccups.

After these rounds, I had to do a behavioral redo. Fortunately, the questions were the same as the first behavioral round, and this time, the interviewer was much more pleasant. I had also refined my stories, which helped immensely.

I heard back from the recruiter in 4 days after the onsite, and then again in just 1 day after a follow-up, confirming that I had passed the Hiring Committee (HC).

Timeline:

The journey was quite long. The recruiter first reached out in early December, which was when I started studying, as I was also exploring internal opportunities within my current company. I finished the onsite interviews in March, making it a total of about four months of preparation and interviewing.