Design and implement a word-guessing game

Q: Design and implement a word-guessing game

This is a System Design interview question from Shopify for Machine Learning Engineer roles. View the full question and solution on PracHub.

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Question

Word-Guessing Game (Wordle-like) — Design and Implement

Context

Build a small, standalone command-line application that lets a user guess a secret word within a limited number of attempts. Treat this like a technical screen: favor clean design, testability, and clear instructions.

Functional Requirements

Dictionary and secret selection
- Read a dictionary file (one word per line).
- Normalize and filter to a fixed length (e.g., 5 letters).
- Select a random secret word from the filtered list.
Input and validation
- Accept guesses via the command line (interactive prompt).
- Enforce fixed length and alphabetic-only input; be case-insensitive.
Feedback per guess
- For each letter in the guess, return feedback:
  - Correct letter in the correct position.
  - Letter present in the word but in a different position.
  - Letter not present in the word.
- Handle duplicate letters correctly.
Attempts and outcomes
- Enforce a maximum number of attempts (e.g., 6).
- Report win/lose outcomes at the end.
Persistent statistics
- Store locally: total games played, total wins, current streak.
- Update after each game finishes.
Tests
- Unit tests for: feedback generation, input validation, word selection, and statistics updates.

Non-Functional/Constraints

Implement in a language of your choice; the result should run as a standalone CLI.
Keep external dependencies minimal.

Deliverables

Source code and dictionary file example.
Build and run instructions.
Brief explanation of key design choices.