Senior Software Engineer at Walmart

How it went

What they would tell you

How to prepare

Their background

Round by round

1. 1

   DSA Coding60 min

   I was asked to implement a search algorithm in a sorted array, and then explain the logic Follow-up: What if the array isn’t sorted? How would you optimize? Then interviewer gave me a classic maze-traversal problem, find the number of islands in a 2D matrix where 1 is land, 0 is water, and islands are connected 1s vertically or horizontally. I chose a DFS approach, explained how it works, and discussed both recursion and stack-based iteration. Follow-up: How would you optimize for very large matrices?

2. 2

   Low-Level Design (LLD)60 min

   I was asked to design the core modules for an online shopping backend user authentication, product catalog, inventory management, shopping cart, order placement, and payment handling.

3. 3

   High-Level Design (HLD)60 min

   Problem: Designing a Ticket Booking System, similar to those used for movies, events, or travel bookings. The system was required to handle the following

   • User searches for available tickets for a particular date and event.
   • Handling real-time booking and preventing double-booking.
   • Integrating payment gateways and generating tickets. Followup - How to handle 10,000 concurrent users trying to book the same 100 tickets?

What came up