HashedIn by Deloitte Interview Experience

First round was OA, it was for 90 minutes and had 3 questions:

• 1 easy and 2 medium LeetCode-type questions.
• But there were no test cases to check if your code was right or not.
• You had to code and check against custom test cases of your own, find the edge cases, and then submit the result.

Technical Interview - Round 1

The next day, I was shortlisted for the 1st round of the technical interview. It started with:

• Introduction – They asked about my passion and extracurricular activities.
• Core subjects like OOPS, C++, and DBMS:
  • Diamond inheritance in C++.
  • Types of Joins in SQL.
  • Virtual Constructor concept.
  • SQL Query – Finding the second largest element in a table.
• Coding Questions – The panel had 2 interviewers (one was asking most of the questions, the other was a bit dormant). I had to write code on paper (only logic explanation was also acceptable).
  • Longest Palindromic Subsequence (LCS variation): Given a string, reverse it and find LCS (from LeetCode Striver Sheet).
  • After solving the optimal approach, they further asked me to find the second largest palindromic subsequence. This was tricky, and I took some time, asked for hints, and was eventually able to solve it, though not in the most optimal way.
  • Another DP question on array partition, which I was able to solve.

Technical Interview - Round 2

In this round, they first asked some basic coding questions:

• Detecting Cycle in a Linked List (Hare and Tortoise method).
• Implementing Stack using Queue.
• System Design:
  • Designing a high-level Flipkart-type app with features they mentioned.
  • I created API call flow diagrams and database schema with foreign key references.
  • They then asked me to normalize the database, guiding me along the way. I made progress but couldn’t complete it exactly as expected.
  • A SQL query based on the tables I created.

HR Round

This was the most chill round:

• Discussion on projects from my resume – why I built them, the purpose, and technical details.
• Casual Questions like CR7 vs Messi, family background, and personal interests.
• Situational Questions like “What would you do if you received ₹10 crore today?”.

If you reach the HR round, you’re likely selected. They selected everyone who made it this far.

Preparation Tips:

• Practice LeetCode (Striver Sheet) for DP, Strings, and Array problems.
• Revise OOPS, DBMS, and SQL queries.
• Learn basic System Design (API design, Database Normalization).
• Mention only the technologies you are confident in on your resume.

Overall, it was a well-structured process, testing DSA, Core CS, and System Design skills.