Design Blackjack and a Deck of Cards Object-Oriented Design Interview
Design a reusable deck of cards and a single-round Blackjack game: cards, suits and ranks, deck shuffle/deal, hand scoring with flexible ace values, player and dealer turns, and terminal outcomes (blackjack, bust, win/lose/push).
1. Problem Statement
Design a reusable deck of cards and a single-round game of Blackjack on top of it. Cover cards, the deck's shuffle and deal, hand scoring (including aces that can count as 1 or 11), the player and dealer turns, and how a round is settled. Start by clarifying scope and the core objects.
2. Live Coding Format
Work in the provided coding workspace while explaining your decisions to the live interviewer. Validation may use inline tests, examples, comments, or a verbal walkthrough.
3. Key Focus Areas
- 1Card/Suit/Rank value objects and Deck shuffle/deal
- 2Hand scoring with flexible ace values and blackjack detection
- 3Round lifecycle: deal, hit/stand, dealer policy, settle
- 4Configurable dealer policy and optional betting value object
4. What Strong Candidates Should Demonstrate
- ✓Model Card, Suit, Rank, and Deck as a reusable, well-encapsulated component.
- ✓Compute blackjack hand values correctly with flexible ace handling.
- ✓Separate deck/card mechanics from game rules and dealer policy.
- ✓Model the round lifecycle and terminal outcomes (blackjack, bust, win/lose/push).
Want interactive feedback?
Practice this problem in the live coding workspace while the interviewer probes your clarification, implementation, trade-offs, and validation.
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