Code Review Best Practices – Lessons from the Trenches

In this article we compile lessons from several company engineering blogs about why and how to conduct code reviews, highlighting their benefits beyond quality assurance, such as team learning, psychological safety, and knowledge sharing.

1. Why perform code reviews? The primary goal is to ensure the quality of introduced changes, but reviews also serve as a communication channel between the author and reviewers, fostering responsibility, psychological safety, and shared best practices.

2. Code reviews as quality assurance A checklist approach (e.g., Casey Rollins' high‑leverage review checklist) helps catch issues that automated tests miss, including architectural consistency, performance, security, readability, and compliance.

Goal alignment – does the change fully satisfy the task requirements; i.e., does the code implement some or all of the specified functionality?

Consistency across the codebase.

Architectural considerations – does the new code fit the existing architecture? Can the new feature improve the architecture, and is it generic or extensible enough?

Simplicity / over‑engineering.

Performance issues – are there specific cases (e.g., peak load) that could break? Do queries pull more data than needed? Would adding an index help?

Accidental errors such as typos or mathematical mistakes – obvious or subtle, especially in math‑heavy code.

Legal/compliance – may be critical depending on the business.

Security issues – any exploitable code? Are keys shared or stored insecurely?

Readability and style – can another developer understand the changes without the author’s explanation?

Best practices – language‑specific best practices and project‑specific conventions.

Localization – are all language‑specific resources correctly localized?

Dependencies – does the change introduce external libraries or APIs? Are there simpler alternatives?

Interaction and side effects – how does the new code interact with the rest of the codebase? Does it break existing functionality? Are related unit tests updated or added?

Logging – is appropriate logging added for debugging?

Exception handling – how are backend exceptions handled and communicated to users?

Testability / test coverage – is the new code covered by automated tests? Are the tests appropriate?

External documentation – does documentation need updating to reflect the change?

3. Code reviews as a team‑building tool Reviews improve team cohesion, provide informal professional development, and expose reviewers to new techniques, design patterns, and alternative solutions.

4. Preparing a pull request for review Keep PRs small and atomic, provide a clear description (the "what, why, where"), ensure all tests pass, and resolve automated review suggestions before requesting human review.

5. Human‑centric reviewing The tone of feedback matters; ask questions, avoid nit‑picking, and focus on constructive, collaborative language that frames issues as team concerns rather than personal faults.

6. Wording matters Reframe harsh comments into team‑oriented suggestions (e.g., "Can we remove duplicate code here?" instead of "You missed this case").

7. Remember to give praise Positive reinforcement, especially for newcomers, makes reviews a supportive experience; acknowledge good work and thoughtful contributions.

The article concludes with references to the original InfoQ translation and the source blog post.