Code Review Best Practices

Code Review Best Practices

Code review is the systematic examination of source code by peers. It's one of the most effective ways to catch bugs, improve code quality, and share knowledge across a team.

The Code Review Process

  CODE REVIEW WORKFLOW
  ====================

  Developer          Reviewer           System
     |                  |                 |
     | 1. Write Code    |                 |
     |------------------>|                 |
     |                  |                 |
     | 2. Submit PR/MR  |                 |
     |----------------------------------> |
     |                  |                 |
     |                  | 3. Review Code  |
     |                  |---------------->|
     |                  |                 |
     |                  | 4. Leave Comments
     |<--------------------------------- |
     |                  |                 |
     | 5. Address Feedback                |
     |------------------>|                 |
     |                  |                 |
     |                  | 6. Approve      |
     |                  |---------------->|
     |                  |                 |
     |                  |   7. Merge      |
     |                  |---------------->|

What to Look For

  REVIEW CHECKLIST
  ================

  Correctness
  - Does the code do what it's supposed to?
  - Are edge cases handled?
  - Are there off-by-one errors?

  Readability
  - Is the code easy to understand?
  - Are variable names descriptive?
  - Are there clear comments where needed?

  Security
  - Is input validated?
  - Are secrets kept out of code?
  - Are there SQL injection or XSS vulnerabilities?

  Performance
  - Are there unnecessary loops or queries?
  - Is caching used appropriately?
  - Are database queries optimized?

  Maintainability
  - Does it follow coding standards?
  - Is it DRY (Don't Repeat Yourself)?
  - Are there tests?

Review Etiquette

• Be constructive: Suggest improvements, don't just criticize
• Be specific: Point to exact lines and explain why
• Ask questions: "Have you considered...?" instead of "This is wrong"
• Praise good work: Acknowledge clever solutions
• Keep it focused: Review code, not the person

Key Takeaways

• Code review catches bugs and improves code quality
• Follow a systematic review process
• Check for correctness, readability, security, and performance
• Be constructive and respectful in feedback