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Walmart·Software Engineer·Technical Phone Screen·Junior

JuniorPrefer not to say
Jun 2026Remote

Summary

Went through a technical phone screen at a FAANG company for a software engineering role. The whole thing nearly got cut short 20 minutes in, which made for a pretty memorable experience for all the wrong reasons.

Questions Asked (1)

Q1

Solve a recursive backtracking problem.

Algorithms & Data Structures
Author's notes

Froze up pretty bad at the start.

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AI HintsAI Generated

Suggested Approach

Start by clarifying the problem and identifying the decision space, constraints, and base cases. Then outline a recursive backtracking solution with pruning, analyze its time/space complexity, and discuss potential optimizations or iterative alternatives.

Pro tip: Demonstrate maturity by discussing trade-offs: when backtracking is appropriate versus dynamic programming or greedy approaches, and how to handle large inputs with pruning and memoization.

1. Clarify the problem

Ask questions to understand input/output, constraints, and edge cases. Confirm whether the solution needs to find all solutions, one solution, or an optimal one.

2. Define the recursive structure

Identify the state parameters, base cases, and the choices at each step. Explain how the recursion explores the decision tree.

3. Implement backtracking with pruning

Write pseudocode or actual code, ensuring to undo choices (backtrack) and incorporate pruning to cut off invalid or non-promising branches early.

4. Analyze complexity and optimize

Discuss time and space complexity, and suggest optimizations like memoization, sorting, or iterative deepening if applicable.

5. Test with examples

Walk through a small example to verify correctness, and consider edge cases like empty input or large constraints.

Key Points to Mention

  • Base case and recursive case definition
  • State space and decision tree
  • Pruning techniques to reduce search space
  • Time and space complexity analysis
  • Trade-offs with other paradigms (DP, greedy)
  • Handling duplicates or constraints (e.g., sorting, visited set)

AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.