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Liftoff·Software Engineer·Take-home Assignment·Intermediate

Intermediate
May 2026

Summary

Liftoff gave me a take-home where I had to implement a working Tetris engine in a terminal. No UI polish needed, just solid logic and clean code structure. It was more involved than I expected going in.

Questions Asked (1)

Q1

Implement a functional Tetris game engine that runs in a terminal, covering the board, all 7 tetrominoes, movement, rotation, gravity, line clears, and game over detection.

Algorithms & Data StructuresSystem DesignTechnical Trade-offs
Author's notes

This took way longer than I budgeted.

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AI HintsAI Generated

Suggested Approach

Start by clarifying requirements and constraints, then outline a modular design separating board, tetromino definitions, and game loop. Walk through core mechanics (movement, rotation, gravity, line clears, game over) with clear data structures and algorithms, and discuss trade-offs like rotation systems and performance.

Pro tip: Mention the Super Rotation System (SRS) and wall kicks early to show domain knowledge, and propose a testable architecture with pure functions for game logic to demonstrate engineering maturity.

1. Clarify Requirements and Constraints

Ask about board size, tetromino representation, rotation system, scoring, levels, and terminal rendering expectations. Confirm whether to implement SRS or a simpler rotation, and if input handling should be non-blocking.

2. Design Data Structures

Define the board as a 2D array (e.g., 10x20) and tetrominoes as matrices or coordinate lists with rotation states. Plan a game state object holding current piece, next piece, score, level, and game over flag.

3. Implement Core Mechanics

Write functions for collision detection, movement (left/right/down), rotation with wall kicks, gravity (timed drop), and line clearing. Ensure game over detection when a new piece cannot spawn.

4. Integrate Game Loop and Rendering

Create a loop that handles input, updates gravity, checks for line clears, and renders the board to the terminal. Use a timer or tick-based system for gravity and handle terminal escape sequences for display.

5. Discuss Trade-offs and Extensibility

Explain choices like SRS vs. simple rotation, array vs. coordinate representation, and how to extend for scoring, levels, or hold piece. Mention testing strategies for game logic.

Key Points to Mention

  • Board representation: 2D array with dimensions and collision detection
  • Tetromino definitions: 7 shapes, rotation states, and SRS wall kicks
  • Game loop: input handling, gravity timing, and rendering
  • Line clearing algorithm: detect full rows, remove, shift down, update score
  • Game over condition: new piece collides at spawn
  • Trade-offs: SRS vs. simple rotation, performance vs. simplicity, testability

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