What is code review?
Length:
3 min
Published:
June 9, 2026
What code review is
Code review is the step where one or more developers read a proposed change before it merges into the shared codebase. The author opens a pull request (or merge request), the reviewers read the diff, ask questions, suggest improvements, and either approve it or ask for changes. Only then does the code land.
The goal is not to police people. It is to catch problems while they are cheap to fix, spread knowledge across the team, and keep the code readable for whoever touches it next.
In plain words
Think of it like a second pair of eyes on an important email before you hit send. You wrote it and it looks fine to you, but a colleague spots the wrong attachment and an unclear sentence. Code review is that check, except the cost of sending the wrong thing is a production bug instead of an awkward reply.
Why it matters
- Catches bugs early. A reviewer often sees the edge case the author missed, before users do.
- Spreads knowledge. More than one person understands each part of the system, which lowers your bus factor.
- Keeps things consistent. Shared conventions and patterns survive because reviewers gently enforce them.
- Lifts juniors. Thoughtful feedback on real code teaches faster than any course.
For us at DX Heroes, smooth code review is a strong signal of healthy developer experience. When reviews are fast and constructive, changes ship quickly and people learn. When they stall, everything slows down.
Common pitfalls
- Reviews that drag on. A pull request sitting for three days blocks the author and invites huge, hard-to-review changes. Keep changes small and review them quickly, ideally the same day.
- Nitpicking over substance. Arguing about formatting wastes everyone's time. Automate style with a linter so reviewers focus on logic and design.
- Rubber-stamping. "Looks good to me" without actually reading the diff gives false confidence. If you approve it, you share responsibility for it.
- Harsh tone. Review the code, not the person. Phrase comments as questions and suggestions, not verdicts.
Related articles:
- What is CI/CD? - The automated checks that run alongside human review.
- What is linting? - Automating style so reviewers can focus on what matters.
- Bus factor - The risk code review helps reduce by spreading knowledge.
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