Prepped this one from a video walkthrough and it paid off.
Start by clarifying requirements and scope (e.g., is it a full game with AI, or just the core engine?). Then design the data model (board, pieces, moves) and outline the core components (game state, move validation, turn management). Finally, discuss trade-offs and potential extensions like AI or networking.
Pro tip: Demonstrate awareness of the difference between a simple implementation and a production-ready system by discussing extensibility, performance, and testing strategies. For example, mention how you would unit test move validation and how you might optimize for AI search.
Ask questions to understand the scope: Is this a full game with UI, AI, or just the engine? What are the constraints (time, memory)? Are there specific features like undo, save/load, or multiplayer?
Define the core objects: Board (8x8 grid), Piece (type, color, position), Move (from, to, special flags). Consider using a 2D array or a map for the board, and discuss representation of pieces (e.g., enums, classes).
Describe the main components: GameState (board, turn, castling rights, en passant, halfmove clock), MoveValidator (checks legal moves, including check/checkmate), and GameController (handles turns, move execution, win conditions).
Talk about trade-offs: e.g., simple vs. efficient move generation, mutable vs. immutable state. Mention how you would extend for AI (minimax, alpha-beta pruning) or networking (serialization, synchronization).
Highlight important edge cases: castling, en passant, pawn promotion, stalemate, threefold repetition. Explain how you would test these (unit tests, integration tests).
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.
Start by stating that the server must be the single source of truth for all timing, and the client should only display a countdown for UX. Then describe a server-authoritative design where the server records move start/end times, validates moves against its own clock, and handles latency and disconnections gracefully.
Pro tip: Emphasize that you'd never trust client-reported time, but you'd still send periodic server time syncs to the client so the displayed timer stays roughly accurate without being authoritative.
Declare that the server owns the clock: it timestamps when a turn begins and when a move is received, and it alone decides if a move was within the time limit.
Use server-side timers with a grace period for network latency; when a move arrives, compare server receipt time against the turn deadline, not any client-supplied timestamp.
Send the client the server's deadline and periodically sync server time so the UI countdown is approximately correct, but never use client time for enforcement.
Cover disconnections, reconnections, clock drift, and malicious clients; use idempotent move submission and server-side timeout events to finalize turns.
Acknowledge latency vs. fairness: a strict server timer may penalize players with slow connections, so consider a small grace period or latency compensation.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.