What is Code Review?

Code review is the practice of having another developer read, run, and discuss a code change before it is merged. The goal is not just to catch typos; reviewers look for incorrect behavior, security issues, missing tests, and choices that will make the code harder to maintain later.

How Does It Work?

In most teams, code review starts with a pull request or merge request. The author keeps the change focused, explains the problem being solved, and reviewers inspect the diff line by line. Useful comments are about behavior, readability, error handling, and tests rather than personal style preferences.

Automated checks usually support the human review: formatting, linting, unit tests, security scans, and build results appear before reviewers approve the change. A clear Git history and well-scoped commits make the review faster and more accurate.

What Do Reviewers Check?

Does the change satisfy the actual business rule?
Are edge cases, errors, and rollback behavior considered?
Do tests cover more than the happy path?
Does the code fit the existing architecture and clean code expectations?

Business Use

Code review is valuable in long-lived products because knowledge about payments, permissions, reporting, or integrations does not stay with one developer. Slow review can still block delivery, so teams usually improve it with smaller pull requests, clear acceptance criteria, and a habit of separating blocking issues from optional suggestions.