Code Review Best Practices: Lessons from the Trenches

In this article we summarize lessons from several companies' engineering blogs about code review, explaining why code reviews are performed and what additional benefits they bring beyond quality assurance, as well as how they help improve team capabilities.

1. What does this article contain?

Why perform code reviews?

Code review as quality assurance

Code review as a team‑growth tool

Preparing a pull request for review

Human‑centric code review

Impact of wording

Code reviews are primarily a formal assessment of changes to ensure quality, but they also serve as a communication channel between the author and reviewers, fostering learning, psychological safety, and best‑practice sharing.

2. Why perform code reviews?

The main purpose is to evaluate the quality of introduced changes, but reviews also help catch issues that automated tests miss, ensure architectural consistency, and promote knowledge transfer.

3. Code review as quality assurance

Reviews catch hard‑to‑automate errors such as architectural mismatches, and they can be used to review test code itself. Using a checklist (as advocated by Casey Rollins) improves coverage of important aspects.

Goal alignment – does the change meet the task requirements?

Code‑base consistency

Architectural considerations

Simplicity vs. over‑engineering

Performance concerns

Accidental bugs (typos, math errors)

Legal compliance

Security issues

Readability and style

Language‑specific best practices

Localization

Dependency management

Interaction and side‑effects

Logging

Exception handling

Testability / coverage

External documentation updates

In addition, reviews should not replace static analysis tools; routine style or naming issues are better handled by linters.

4. Code review as a team‑growth tool

Effective reviews increase team cohesion, provide informal professional development, and enable knowledge sharing. They also improve communication, making remote teams more connected.

5. Preparing a pull request – helping reviewers

Keep PRs atomic – focus on a single bug, feature, or API change.

Provide a clear description that acts as a map for reviewers.

Test locally and ensure the PR passes builds and automated checks before requesting review.

6. Human‑centric code review

Pay attention to tone: ask questions instead of jumping to conclusions, avoid nit‑picking trivial issues, be pragmatic about what to block, and include examples or documentation when helpful.

7. Wording makes a big difference

Use constructive language that frames feedback as a team effort (e.g., “Can we remove this duplicate code?” instead of “You missed this”).

8. Don’t forget praise

Recognize good work and effort, especially for newcomers, to create a positive review experience and encourage continued learning.

Author introduction: Drazen Zaric – analyst/data‑science generalist with experience in mobile gaming data engineering, warehouse design, product analytics, data science, and product management.