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rippling·Software Engineer·Technical Phone Screen·Intermediate

Intermediate
Jun 2026

Summary

Rippling SWE interview with a coding problem that had a tricky follow-up about handling incomplete inputs. Nothing too wild but the edge case caught me off guard.

Questions Asked (1)

Q1

Given two poker hands, determine which one wins. Follow-up: if both hands are incomplete, output UNKNOWN when a winner cannot be determined (e.g. 9999 vs 9).

Algorithms & Data StructuresTechnical Trade-offs
Author's notes

The base case was manageable but the follow-up tripped me up.

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AI HintsAI Generated

Suggested Approach

Clarify the rules for hand comparison, including handling incomplete hands and the UNKNOWN case. Design a modular evaluator that ranks complete hands and returns UNKNOWN when a winner cannot be determined due to missing cards. Discuss trade-offs between simplicity and extensibility.

Pro tip: Explicitly define what 'incomplete' means and when UNKNOWN applies, as ambiguity here is a common trap. Show you can balance correctness with practical constraints like performance and code clarity.

1. Clarify Requirements

Ask about hand representation, comparison rules, and the exact conditions for UNKNOWN. Confirm whether incomplete hands can ever win or only lead to UNKNOWN.

2. Design Hand Evaluation

Outline a function to evaluate a complete hand's rank (e.g., pair, straight) and compare two hands. For incomplete hands, define logic to detect if a winner is determinable.

3. Handle Incomplete Hands

Explain how to compare incomplete hands: if one hand's best possible completion cannot beat the other's current best, return the winner; otherwise UNKNOWN. Use examples like 9999 vs 9.

4. Implement and Test

Write modular code with clear separation between evaluation and comparison. Test edge cases: both complete, both incomplete, one complete, and ambiguous scenarios.

5. Discuss Trade-offs

Mention performance (e.g., precomputing ranks), extensibility (adding new hand types), and simplicity. Consider if UNKNOWN should be a special return value or exception.

Key Points to Mention

  • Hand ranking algorithm (e.g., evaluate 5-card hand strength)
  • Comparison logic for complete hands (tie-breaking rules)
  • Definition of incomplete hand and UNKNOWN condition
  • Edge cases: empty hand, one card, multiple incomplete hands
  • Time/space complexity and optimization opportunities
  • Modular design for easy testing and extension

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