Hackerrank | Backend Engineer 2 | Bangalore | Rejected
Summary
I interviewed for a Backend Engineer 2 position at HackerRank in Bangalore, completed a DSA round and a system‑design round, but was ultimately rejected.
Full Experience
Status: 2.10 YOE Position: Backend Engineer 2 Location: Bangalore
Round 1: DSA
- Question 1: Easy question based on HashMaps. Similar to Two Sum: https://leetcode.com/problems/two-sum/
- Question 2: Given a list of strings, check if for any string, any of its permutations is divisible by 8. (Math trick: A number is divisible by 8 if its last 3 digits are divisible by 8. You just need to check permutations of combinations of 3 digits).
- Result: Discussed the approach and wrote the code. For the second question, the approach was agreed upon and I completed the code, couldn't run it for all test cases in interest of time.
Round 2: HLD
- Question: Design a test‑taking platform (essentially, design HackerRank).
- The interviewer focused very heavily on the specific database schemas for
codeStubsandtestCases. They wanted a highly optimal structure for execution and storage.
Verdict: Rejected.
Interview Questions (3)
Two Sum (HashMap variant)
Given an array of integers, find the indices of the two numbers such that they add up to a specific target. Use a hash map to achieve O(n) time complexity.
Permutation Divisible by 8
Given a list of strings, determine if any permutation of any string is divisible by 8. A number is divisible by 8 if its last three digits form a number divisible by 8, so only permutations of 3‑digit subsets need to be checked.
Design a Test‑Taking Platform
Design a platform similar to HackerRank where users can take coding tests. Focus on database schema design for codeStubs and testCases to allow highly optimal execution and storage.