← Early-stage Startup Interview Insights

Early-stage Startup·Software Engineer·Technical Phone Screen·Junior

JuniorPending
Jun 2026Remote

Summary

Live coding round where I had to implement a checkers game from scratch in 20 minutes. Got deep into move validation and basically ran out of time before touching the parts that probably actually mattered.

Questions Asked (1)

Q1

Implement a checkers game, including board setup, move validation, making moves, and win condition logic.

Algorithms & Data StructuresTechnical Trade-offs
Author's notes

I went way too deep on validation.

Create a free account to read the full note

AI HintsAI Generated

Suggested Approach

Start by clarifying the rules and scope (e.g., standard checkers, board size, mandatory captures) to align with the interviewer. Then outline a clean object-oriented design with separate classes for Board, Piece, and Game, focusing on modularity and testability. Finally, walk through the implementation of move validation, capture logic, and win condition, discussing trade-offs and potential optimizations.

Pro tip: Discuss how you would test the game logic, including edge cases like multiple captures and stalemates, to demonstrate a quality-focused mindset. Also, mention how you might extend the design for variants (e.g., international draughts) to show foresight.

1. Clarify Requirements

Ask questions to confirm the rules: board size (8x8), piece movement (diagonal forward, kings move backward), mandatory captures, and win conditions (no moves or no pieces).

2. Design Data Structures

Propose classes: Board (2D array of Piece objects), Piece (color, isKing), and Game (turn, move history). Consider using enums for colors and directions.

3. Implement Move Validation

Write a method to validate moves: check diagonal movement, forward direction for non-kings, capture jumps, and mandatory capture rule. Ensure moves stay within bounds.

4. Implement Move Execution and Win Check

Apply moves, handle captures (remove opponent piece), promote to king, and switch turns. After each move, check if the opponent has any legal moves; if not, declare winner.

5. Discuss Trade-offs and Testing

Talk about design choices (e.g., immutable vs mutable board), performance considerations, and how you would unit test each component, including edge cases.

Key Points to Mention

  • Object-oriented design with clear separation of concerns (Board, Piece, Game).
  • Move validation logic: diagonal moves, captures, mandatory captures, and king promotion.
  • Win condition: opponent has no legal moves or no pieces left.
  • Handling edge cases: multiple captures, stalemate, and boundary checks.
  • Testing strategy: unit tests for move validation, capture sequences, and win detection.
  • Extensibility: how to adapt for different rule sets or board sizes.

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