Hackerrank | Backend Engineer 2 | Dec 2025

Round-1: OA

Questions - https://leetcode.com/discuss/post/7321136/hackerrank-backend-engineer-ai-interview-lu0j/

Round-2: DSA

1. Based on heap, top k variant
2. there are n friends, and given an array(1 based index) representing array[i] is where ith friend throws ball to, and k return which friend has ball at time k if friend 1 throws ball at time = 1

n = 6
arr = [2, 3, 4, 5, 3, 6]
k = 10

ans - friend 4

Round-3: System Design

Design Real time messaging system.

Verdict - rejected.

i still don't know where i went wrong.