Shopify·Software Engineer·Onsite - Coding / Algorithms·Intermediate

Intermediate

Jun 2026

Summary

Shopify software engineering interview with a coding round built around designing a Wordle-style game from scratch. The problem had more edge cases than it looked like at first glance, and there was apparently a component where you might have to read someone else's generated code and find bugs in it too.

Questions Asked (1)

Design and implement a four-letter word guessing game with a clean API. The game accepts guesses against a target word from a dictionary, rejects invalid inputs without counting them as attempts, and returns a positional hint string using Wordle-style duplicate-letter matching rules.

API & IntegrationsAlgorithms & Data StructuresSystem Design

Author's notes

The basic loop was fine, I got the structure down pretty fast.

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AI HintsAI Generated

Suggested Approach

Start by clarifying requirements and defining the API contract, then outline the core algorithm for duplicate-letter matching, and finally discuss implementation details, edge cases, and testing. Emphasize clean code, separation of concerns, and robust validation.

Pro tip: Demonstrate maturity by proactively discussing how you would handle edge cases like repeated letters and invalid inputs, and by suggesting a test-driven approach to ensure correctness.

1. Clarify Requirements and Define API

Ask clarifying questions about dictionary size, target word selection, guess validation rules, and hint format. Define the API endpoints or methods, including input parameters and return types.

2. Design the Core Algorithm

Outline the two-pass algorithm for duplicate-letter matching: first mark exact matches, then handle remaining letters with a frequency map to avoid over-counting.

3. Implement with Clean Code

Write modular code with clear separation between input validation, game logic, and hint generation. Use appropriate data structures like maps for letter counts.

4. Handle Edge Cases and Validation

Ensure invalid inputs (wrong length, non-alphabetic, not in dictionary) are rejected without incrementing attempt count. Discuss how to handle repeated guesses or game-over conditions.

5. Test and Iterate

Propose unit tests covering normal cases, duplicate letters, invalid inputs, and boundary conditions. Mention performance considerations for large dictionaries.

Key Points to Mention

Two-pass algorithm for duplicate-letter matching (exact matches first, then remaining letters with frequency counting)
Input validation: length check, alphabetic check, dictionary membership, and not counting invalid attempts
API design: clear method signatures, return types (e.g., hint string, game state), and error handling
Data structures: using hash maps for letter frequencies and sets for dictionary lookup for O(1) average time
Edge cases: repeated letters, all correct, no correct, game over conditions, and attempt limits
Testing strategy: unit tests for algorithm correctness and integration tests for API behavior

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