How to Prepare for a Code Review Interview Round

More companies now include a code review round: you get a pull request or a short file and are asked to review it as if a teammate wrote it. It tests judgment and communication more than raw algorithm skill. Here is how to prepare.

What interviewers are looking for

• Prioritization. Can you tell a correctness bug from a style nit, and say which matters more?
• Clear, kind feedback. Would your comments help a junior engineer, or make them defensive?
• Context questions. Do you ask what the code is for before judging it?
• Testing instinct. Do you notice missing tests and edge cases?

A simple review order

1. Read the description first. Say out loud what the change is supposed to do. If there is no description, ask.
2. Check correctness. Off-by-one errors, null or empty inputs, error handling, concurrency, and resource leaks.
3. Check security and data safety. Unvalidated input, SQL built from strings, secrets in code, logging personal data.
4. Check design. Is the logic in the right place? Is something duplicated that already exists?
5. Check tests. What is tested, and what obvious case is missing?
6. Only then, readability. Naming, long functions, comments.

How to phrase comments

Label severity so the author knows what blocks the merge:

• "Blocking: this loop skips the last element when n is even."
• "Suggestion: this could reuse parseDate() from utils."
• "Nit: tmp2 could be named retryCount."

Ask questions when you are unsure ("Is this called from multiple threads?") instead of stating guesses as facts. And mention one thing the author did well. Interviewers notice it.

Practice ideas

• Review open pull requests in a project you use and compare your notes with the maintainers' comments.
• Take an old piece of your own code and review it as if a stranger wrote it.
• Time-box yourself to 20 minutes, which is typical for this round.

Wrapping up

End your review with a short summary: "Two blocking issues, one around empty input and one SQL injection risk; the rest are suggestions. Overall the structure is easy to follow."

If you want to rehearse explaining your reasoning out loud, an AI assistant for technical interviews such as Linkjob AI can help you practise (disclosure: I work on Linkjob AI). The habit that matters most is the same either way: prioritize, explain, and stay constructive.