Walmart SDE Interview Experience | Cleared 3-Round Virtual Onsite

Hi everyone, I recently completed the Walmart SDE Virtual Onsite interview and successfully passed all three rounds, receiving an offer in the end.

Overall, Walmart’s VO process is well-structured with a clear evaluation focus. They place strong emphasis on practical system design, real-world collaboration experience, and solid coding fundamentals. The interviewers were friendly and often guided the discussion, but they also dug deep into details.

Here’s a breakdown of my full interview experience and key takeaways.

Round 1: System Design (Design a Scalable Notification Service)

This round was led by a senior interviewer. He first asked me to clarify requirements before moving step by step into system design.

I started by defining functional requirements such as real-time vs batch notifications and multi-channel delivery. Then I covered non-functional requirements including high availability, scalability, and idempotency.

For the architecture, I proposed a design including:

API Gateway
Kafka as the message queue
Worker services for processing
Redis and Cassandra for storage

I also discussed horizontal scaling, rate limiting, circuit breaking, and dead letter queues. The interviewer focused heavily on idempotency handling and high-concurrency bottlenecks. I answered these based on my past project experience, which seemed to resonate well.

Takeaway: Walmart values practical and implementable designs. Clearly explaining trade-offs is more important than chasing a “perfect” architecture.

Round 2: Behavioral Questions (BQ)

This round focused on real-world collaboration scenarios. The atmosphere was relaxed, but the interviewer asked detailed follow-up questions.

Topics included:

Leading cross-team projects and resolving priority conflicts
Handling disagreements on technical solutions
Optimizing slow or unstable systems under pressure
Dealing with compliance-related issues

I answered all questions using the STAR method, emphasizing context, actions, and measurable results. The interviewer appreciated my sense of ownership and conflict resolution skills.

Takeaway: Prepare 5–6 strong STAR stories in advance, covering leadership, conflict, optimization, and compliance. Quantifiable results make a big difference.

Round 3: Coding (Cycle Detection in Directed Graph)

This round was conducted by an engineer. The problem was detecting cycles in a directed graph, including edge cases like multiple components, self-loops, and duplicate edges.

I implemented a DFS solution using a coloring method. Before coding, I proactively discussed edge cases. After finishing, I was asked how to find all cycles in the graph, which I explained conceptually.

The overall process went smoothly, and the interviewer was satisfied with both my approach and implementation.

Takeaway: Walmart doesn’t expect perfect code, but they do expect clear thinking, solid handling of edge cases, and good communication. Explicitly stating edge cases after coding helps a lot.

Final Thoughts and Preparation Tips

Walmart’s SDE VO evaluates candidates in a balanced way:

System Design: depth and practicality
Behavioral: real experience and ownership
Coding: fundamentals and clarity

Key preparation strategies:

Practice system design scenarios like e-commerce, notifications, and payments, focusing on trade-offs
Prepare 5–6 STAR stories for behavioral interviews
Practice graph problems and simulation questions for coding
Stay calm and structured during interviews

Resources Recommendation

If you're also preparing for Walmart, Amazon, or other big tech companies and feel that self-preparation is not efficient enough, I recommend checking out Programhelp.

They offer experienced mentorship from engineers who have gone through similar interview processes. Their strengths include system design structuring, refining STAR stories, and optimizing coding approaches. They also provide targeted mock interviews based on your background.

If you're unsure how to improve your preparation strategy, it’s worth taking a look.