rippling·Software Engineer·Technical Phone Screen·Intermediate

Intermediate

May 2026

Summary

Rippling SWE screen that was basically a multi-part OOD problem dressed up as a card game. Three progressively harder parts, and they told you upfront to at least get through part two before time ran out.

Questions Asked (1)

Design and implement a class structure to represent a poker hand and classify it by type (five-of-a-kind, four-of-a-kind, full house, three-of-a-kind, two pair, one pair, or high card). Then extend it to compare two hands, first by hand type and then card by card left to right if types are tied. Finally, given a list of hands with associated bids, sort them by strength and compute total winnings as the sum of each hand's rank multiplied by its bid.

Algorithms & Data StructuresSystem DesignTechnical Trade-offs

Author's notes

Three parts stacked into one problem.

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AI HintsAI Generated

Suggested Approach

Start by clarifying the rules and constraints, then design a modular class structure with a Hand class that encapsulates cards and hand type, and a HandEvaluator for classification and comparison. Implement classification using frequency counts, comparison using lexicographic ordering of sorted card values, and finally sort hands by strength to compute winnings.

Pro tip: Mention that you would separate the evaluation logic from the Hand data structure to make it testable and extensible, and discuss how you would handle edge cases like ties in the final ranking.

1. Clarify Requirements and Constraints

Ask about card representation, hand size, ranking order of hand types, and whether suits matter. Confirm the input format for hands and bids.

2. Design Class Structure

Propose a Card class (suit, rank), a Hand class (list of cards, bid), and a HandEvaluator class with methods to classify and compare hands. Consider using enums for hand types and ranks.

3. Implement Hand Classification

Use a frequency map of card ranks to determine hand type. For five-of-a-kind, check if the deck includes jokers or wildcards; otherwise, it's impossible with a standard deck.

4. Implement Hand Comparison

Compare hands first by hand type (using an ordered enum). If tied, compare card ranks in descending order (or as specified) to break ties.

5. Compute Total Winnings

Sort the list of hands by strength (weakest to strongest), assign ranks starting from 1, and sum rank * bid for each hand.

Key Points to Mention

Use of frequency counting (e.g., hash map) for efficient hand classification.
Ordered enum or integer mapping for hand types to simplify comparison.
Lexicographic comparison of sorted card ranks for tie-breaking.
Separation of concerns: Hand as data, Evaluator as logic.
Handling of edge cases: five-of-a-kind with wildcards, ties in final ranking.
Time and space complexity: O(n log n) for sorting, O(n) for evaluation.

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