Meta·Software Engineer·Onsite - Coding / Algorithms·Senior

Senior

Apr 2026

Summary

Meta SWE coding round where you build a card game from scratch with an AI assistant, iterating on the design live as new requirements get thrown at you. More open-ended than I expected, less about grinding leetcode and more about whether you can actually architect something under pressure.

Questions Asked (1)

Design and implement a card game from scratch: define the data model for the deck, players, and game state, then expose operations like shuffle, deal, play a card, score a round, and detect end-of-game. Write a driver that simulates a full game, and be ready to refactor as new requirements come in.

Data ModelingSystem DesignTechnical Trade-offs

Author's notes

This one took me a minute to get my footing.

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AI HintsAI Generated

Suggested Approach

Start by clarifying the game rules and requirements, then design a clean data model with clear separation of concerns (deck, player, game state). Implement core operations as pure functions where possible, and write a driver that simulates a full game. Be prepared to discuss trade-offs and how you would refactor for new requirements.

Pro tip: Demonstrate extensibility by designing interfaces that allow easy addition of new card types or game rules, and mention how you would test each component in isolation.

1. Clarify Requirements and Scope

Ask questions to understand the specific card game rules, number of players, win conditions, and any constraints. Define the scope of the MVP and potential future extensions.

2. Design Data Model

Define classes/structs for Card, Deck, Player, and GameState. Consider immutability, encapsulation, and relationships. Use appropriate data structures (e.g., list for deck, map for player hands).

3. Implement Core Operations

Write methods for shuffle, deal, playCard, scoreRound, and isGameOver. Ensure they are testable and handle edge cases (e.g., empty deck, invalid moves).

4. Write Driver and Simulate Game

Create a driver that initializes the game, runs the main loop, and outputs the results. Use the operations to simulate a full game from start to finish.

5. Discuss Refactoring and Extensibility

Explain how you would refactor to accommodate new requirements (e.g., new card types, additional players) and how design patterns (e.g., Strategy, Factory) could help.

Key Points to Mention

Separation of concerns: keep game logic separate from I/O and UI.
Use of appropriate data structures and algorithms (e.g., Fisher-Yates shuffle).
Handling edge cases and error conditions (e.g., invalid plays, empty deck).
Testability: design for unit testing each component.
Extensibility: use interfaces and design patterns to allow easy addition of new rules or card types.
Trade-offs: discuss time/space complexity, immutability vs. mutability, and simplicity vs. flexibility.

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