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System Design questions require understanding of core concepts and practice. PracHub provides solutions with explanations to help you master system design interviews.

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This is a medium difficulty System Design question, commonly asked during Technical Screen rounds at Shopify.

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This question is commonly asked for Machine Learning Engineer candidates at Shopify during technical interviews.

Design and implement a word-guessing game | Shopify Interview Question

Quick Overview

This question evaluates programming and system-design competencies such as command-line application architecture, input validation, feedback logic, state persistence for statistics, and unit testing for correctness and edge-case handling, and is categorized under System Design.

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.

Quick Overview

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.

Design and implement a word-guessing game

Quick Overview

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

Context

Functional Requirements

Non-Functional/Constraints

Deliverables

Solution

Comments (0)

Design and implement a word-guessing game

Quick Overview

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

Context

Functional Requirements

Non-Functional/Constraints

Deliverables

Solution

Comments (0)