My HashedIn by Deloitte Interview Experience | Backend + GenAI Role (2 YOE)

I wanted to share my detailed interview experience for the Python/Backend + GenAI role at HashedIn by Deloitte, which I recently went through.
I connected with the recruiter directly through LinkedIn, and the process moved fairly quickly.

🔹 Round 1: DSA + SQL (Online Coding + Technical Q&A)

The first round consisted of 2 DSA coding questions + 2 SQL questions.

Coding Questions:

1️⃣ Best Time to Buy and Sell Stock (Max Profit)

2️⃣ Search in a 2D Matrix

Efficient binary search approach over sorted rows/columns.

SQL Questions:

Swap Sex of Employees

The round mainly tested consistency with common interview patterns.

🔹 Round 2: LLD + HLD Discussion (System Design)

This was the most interesting round.

I was asked to design a multi-tenant e-commerce platform (like Amazon) that supports:

Multiple vendors (tenants)

Each tenant having separate product catalogs

Shared infrastructure with isolation

Scalability, caching, availability, and partitioning

API design

Database schema

Trade-offs between monolith vs microservices

Handling high read/write traffic

We went deep into:

Tenant isolation strategies

Choice of database (SQL vs NoSQL)

Designing cart, order, product catalog

Cache layers (Redis)

Event-driven flow using Kafka

Rate limiting, throttling, API Gateway

Deployment & scaling assumptions

This round checked architectural thinking, clarity, and trade-offs.

🔹 Round 3: Managerial + Behavioral Round

This round was mostly to evaluate:

My previous project experience

Ownership and problem-solving

How I handled production issues

Collaboration, communication, and mindset

Cultural fit for HashedIn’s engineering environment

Some of the questions included:

Walkthrough of my recent project

How I debug production bugs

Times I worked under pressure

Conflict resolution within a team

Motivation for switching roles

Overall, the manager focused more on fitment than pure technicals.

🔹 Offer Discussion & Outcome

After clearing all rounds, I moved into salary discussion.