Walmart·Software Engineer·Technical Phone Screen
Apr 2026
Walmart Labs SWE interview, one algorithmic question that sounds easy until you actually think about the edge cases. They wanted the full treatment: algorithm, correctness argument, complexity analysis.
- Given N bus routes each with a start time (inclusive) and end time (exclusive), find the maximum number of routes that are running at the same time. Walk through your algorithm, explain why it's correct, and give the time and space complexity.
“My first instinct was brute force, check every pair of intervals, which I knew was wrong but I said it anyway to buy time.” The rest of the author's notes on Software Engineer interview at Walmart, Technical Phone Screen round, covers how they worked through the question, what the panel pushed back on, and what they would do differently.
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