How to Excel at Code Reviews: 13 Standards for Effective Reviews

How to Excel at Code Reviews

In this article we briefly introduce 13 code review standards that can greatly help improve software health and keep developers satisfied.

As the name suggests, code review is a process where one or more developers examine code written by another developer (the author) to ensure:

The code has no errors or issues.

It meets all quality requirements and standards.

The code passes the intended tests.

After merging, it improves the health of the codebase.

This is why code review is a critical part of software development. Reviewers act as codebase custodians, determining whether code is ready to become part of the repository and go into production.

Google is known for its excellent engineering practices and has effective code review standards that highlight key points to remember when reviewing code. At Google, the main goal of code review is to ensure the overall health of the codebase continuously improves over time.

Here is the list of items to keep in mind when looking at a change list.

Review Standards

1. The change improves the overall health of the system

Every change list (Pull Request) should improve the overall health of the system. The idea is that small improvements accumulate, so each merge makes the software or codebase healthier.

2. Fast code review, response and feedback

First, do not delay pushing (merging) better code. Do not expect code to be perfect. If it can improve the system’s health, push it.

“The key here is that there is no ‘perfect’ code, only better code.”

If you are not in the middle of a high‑priority task, review the code as soon as it is finished; otherwise, a working day is the maximum time to respond to a pull request. Expect the change list to receive multiple rounds of partial/full review within a day.

3. Educate and inspire during the review

Provide guidance by sharing knowledge and experience as much as possible during the review.

4. Follow standards when reviewing code

Always remember that coding standards and style guides are the ultimate authority during a review. For example, refer to the coding conventions to keep consistency between tabs and spaces.

5. Resolve review conflicts

Resolve conflicts by following agreed‑upon best practices in style guides and coding standards, and by seeking advice from more experienced people in the product domain. The handling varies according to severity.

If your comment is optional or minor, note it in the comment and let the author decide whether to address it. As a reviewer, you can at least suggest that the change list stay consistent with the rest of the codebase even without a style guide.

6. Demonstrate UI changes as part of the review

If the pull request changes the user interface, a demonstration is required in addition to code inspection to ensure the visual appearance matches expectations and mockups.

For front‑end pull requests, it is always recommended to perform a demo/run‑through or ensure the change list includes necessary UI automation tests to verify added/updated functionality.

7. Ensure the review is accompanied by all tests

Unless it is an emergency, a pull request should be accompanied by all necessary tests such as unit, integration, end‑to‑end, etc.

Emergencies may be critical bugs or security vulnerabilities that need a quick fix; in such cases, create appropriate tickets and ensure ownership for post‑hot‑fix verification.

There is never a sufficient reason to skip testing. If time constraints make some goals risky, the solution is not to skip tests but to scope the deliverable.

8. Stay focused and avoid interruptions while reviewing

If you are in a period of focused work, do not disturb yourself, as it may take a long time to get back into flow. In other words, the cost of interrupting a focused developer is higher than making them wait for a review. Perform reviews after scheduled breaks (e.g., lunch, coffee).

It is not expected to finish and merge the entire review in a single day. The important thing is to give the author quick feedback. You may not be able to do a full check, but you can point out items for further investigation, greatly reducing frustration during the review.

9. Review everything, make no assumptions

Examine every line of code assigned to you. Do not make assumptions about manually written classes and methods, and ensure you understand what the code does.

Make sure you understand the code you are reviewing. If not, ask for clarification or a walkthrough. If part of the code is beyond your expertise, ensure another qualified developer can review those parts.

10. Keep the big picture in mind when reviewing

Viewing changes in a broader context is helpful. For example, a file changed with four new lines. Do not look only at the four lines; instead, consider the whole file and assess whether the new code degrades existing quality or creates refactoring candidates.

If you review such small additions outside the function/method/class context, over time you will inherit a class that is unmaintainable, overly complex, hard to test, and difficult to extend or refactor.

Remember that over time, many small improvements add up to a high‑quality product with minimal defects, while small degradations and technical debt accumulate and make the product harder to maintain and scale.

11. Recognize and encourage good work during the review

If you see something good in a change list, acknowledge the author’s excellent work and encourage them. Code review should not only find bugs but also motivate and guide developers.

12. Be courteous, respectful, kind and clear

It is essential to be kind, clear, polite and respectful during the review, and to be very clear and helpful to the author. Comment on the code, not the developer.

13. Explain your review comments and keep scope in mind

Whenever you suggest an alternative or raise a flag, explain the reason and provide examples from your knowledge and experience to help the developer understand how your suggestion improves code quality.

When recommending a fix or change, strike a balance between guidance, explanation, tips or suggestions rather than providing a complete solution.

Thank you for reading; I hope you enjoyed the article. Feel free to leave comments or suggestions in the public account.