Meta E4 Interview Experience

My Meta E4 Interview Experience

I recently interviewed with Meta for their Product role at the E4 level and wanted to share my experience across the phone screen and onsite rounds.

Before the phone interview, I completed two assessments:

• A coding assessment with 4 stages
• A work-style assessment

Phone Screen

1. Count number of 1s in a given subarray in a large array of 1s and 0s. I was given indices for the start and end of the subarray. I started with a simple linear approach, then optimized it to a prefix-sum solution: prefix[end] - prefix[start - 1]. Follow-ups included questions on handling digits 0–9 instead of binary, and how to handle cases like start > end.
2. Find Lowest Common Ancestor of a Binary Tree. I implemented the standard recursive LCA algorithm and walked through examples. I missed one edge case where p and q have the same value, and needed a small hint for the scenario where both references point to the same node.

Overall Phone Screen Feedback was positive: strong coding, clear communication, and fast implementation. Improvements were suggested in clarifying questions and edge-case coverage.

Onsite Rounds

Round 1

1. Find first 1 in a sorted binary matrix. I solved this problem cleanly.
2. Trapping Rain Water. I solved this problem cleanly.

Round 2 (Design Round)

I was asked to design a concert ticket booking service for a small scale (one venue, many concerts). I discussed requirements, user flows, API design, data model, and bottlenecks. I drove the conversation end-to-end, providing detailed but clear explanations, and moved quickly through the design choices. I also pushed back when needed to clarify assumptions.

Round 3

1. Valid Palindrome II.
2. Valid Word Abbreviation.

I solved both of these problems without any issues.

Round 4 (Behavioral)

This was a standard behavioral round with questions focused on handling ambiguity, conflict resolution, and using data to drive decisions. It was a straightforward conversation centered around my past experiences, demonstrating ownership, and highlighting collaborative efforts.