Interview coding tests often vary by role, but here’s a breakdown of the most common types across software engineering interviews:

Algorithm & Data Structure Challenges

These are the bread and butter of technical interviews, especially for general software engineering roles.

• Array and String Manipulation: Reverse arrays, find duplicates, substring problems
• Sorting and Searching: Implement quicksort, binary search, merge intervals
• Recursion and Backtracking: N-Queens, Sudoku solver, permutations
• Hash Maps and Sets: Group anagrams, two-sum, longest substring without repeating characters
• Trees and Graphs: BFS, DFS, lowest common ancestor, cycle detection
• Dynamic Programming: Knapsack, coin change, longest increasing subsequence

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System Design Questions

More common for mid-to-senior roles or backend-focused positions.

• Design Twitter / URL Shortener / Rate Limiter
• Scalability and Load Balancing
• Database Schema Design
• Caching Strategies
• API Design and Versioning

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Practical Coding Tasks

These simulate real-world development and are often part of take-home assignments or live coding.

• Build a CRUD app (e.g., with Express, Django, or Rails)
• Consume and manipulate APIs (e.g., fetch GitHub repos and display them)
• DOM manipulation (for frontend roles)
• State management (React Context, Redux, or Recoil)
• Unit testing (e.g., with Jest, Mocha, or JUnit)

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Language-Specific Quirks

Tests may include questions that probe your understanding of the language’s nuances.

• JavaScript: Closures, hoisting, event loop, async/await
• Python: List comprehensions, decorators, generators
• Java: OOP principles, concurrency, memory management

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DevOps & Infrastructure

For roles involving automation or cloud services.

• Write a Kubernetes CronJob
• Create a CI/CD pipeline
• Configure Helm charts
• Set up logging and monitoring

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Behavioral & Problem-Solving Interviews

Not code-heavy, but still technical.

• Talk through a bug you solved
• Explain trade-offs in a past architecture decision
• How do you handle technical debt or legacy code?

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