Walmart Drive : 17 April IN4 | SSE
Summary
I interviewed for a Senior Software Engineer role at Walmart, completing three rounds (LLD, DSA, and HLD) and am currently awaiting the final decision.
Full Experience
Walmart Drive : 17 April IN4 | SSE 6+ YOE Waiting for results - Anyone else?
Round 1 : LLD or DSA- LLD in my case, notification service LLD and resume questions about kafka, event driven architecture, java spring boot , CI/CD , docker, k8s, container, how we use these.
Self : Hire
Round 2 : 2 DSA leetcode medium 1. meeting schedule 2. number and name of islands (dfs/bfs) - no code just intution, for me done in 8-10mins then she asked java questions and then deep dive into 3. LRU and LFU cache LLD
Self evaluation : Strong Hire
Round 3 Onsite : HLD round : 1. What will you do to manage planned 100x traffic for your application. 1. before bussiness layer 2. after bussiness layer 3. On the day of incoming traffic. 2. E-commerce checkout service given the functional requirement and how will I hanlde Black Friday kind of sale. follow up tradeoff questions checkout service - 1. fetch user details - payment types etc. 2. check the stock in inventory 3. after selecting the address inventory based on address 4. payment happens 5. place order 6. send success or failure to user
The interviewer was somewhat confrontational and disengaged. They opposed my initial approach to the first question without providing guidance, only saying 'ok' once I hit their desired answer. During the checkout design, I started with post-cart flows, but the interviewer instructed me to draw components first. Because I had to pivot, and with limited time left, I ended up juggling the flow explanations and questions in an unstructured manner(got to know at last from interviewer as feedback). Although I gave all of his answers but somehow he never said OK :(
Interviewer feedback only 2 things: 1. unstructered explanation 2. Conceptually fine
Self evaluation : Hire : if interviwer is just putting me in pressure situation Reject : If he gave importance to unstructured > conceptual understanding.
What do you huys think.... will I get call for next rounds
Interview Questions (3)
Number and Name of Islands
Given a grid consisting of land and water cells, determine the number of distinct islands and assign a unique name or identifier to each island using either Depth‑First Search (DFS) or Breadth‑First Search (BFS). The problem focuses on counting islands and labeling them, without requiring actual code implementation in the interview.
Design LRU and LFU Cache
Design a low‑level (LLD) solution for implementing both Least Recently Used (LRU) and Least Frequently Used (LFU) cache mechanisms. The candidate was expected to discuss data structures, eviction policies, and API design for these caches.
E‑commerce Checkout Service Design
Design an e‑commerce checkout service that can handle Black Friday‑style traffic spikes. The functional requirements discussed included:
- Fetching user details (payment types, etc.)
- Checking inventory stock
- Handling address‑based inventory considerations
- Processing payment
- Placing the order
- Sending success or failure response to the user