The Art of Code Review

Code reviews are where good code becomes great code. They're also where team culture is built, knowledge is shared, and standards are maintained. Yet many teams treat code review as a mere checkbox in their development process.

Great code reviews are an art form—balancing technical rigor with human empathy, catching bugs while fostering growth, and maintaining quality without slowing down delivery.

The Foundation: Mindset Over Process

Review the Code, Not the Person

❌ "This is wrong and makes no sense"
✅ "Consider using a Map here for O(1) lookups instead of O(n) array scanning"

❌ "You always forget error handling"
✅ "What happens if the API call fails here?"

Ask Questions, Don't Give Commands

❌ "Change this to use async/await"
✅ "Would async/await be clearer than Promise chains here?"

❌ "This needs better variable names"
✅ "Could we make these variable names more descriptive? Maybe `userPreferences` instead of `prefs`?"

What to Look For

Architecture and Design Patterns

• Does this solution fit the existing codebase architecture?
• Are there simpler approaches that would work just as well?
• Does this introduce any coupling that could cause problems later?

Code Quality and Maintainability

// Instead of reviewing every line, focus on patterns
// Look for: unclear naming, missing error handling, complex logic

// This could be simplified
const getUserData = async (userId) => {
  try {
    const response = await fetch(`/api/users/${userId}`)
    if (!response.ok) {
      throw new Error('Failed to fetch user')
    }
    const data = await response.json()
    return data
  } catch (error) {
    console.error(error)
    return null
  }
}

// Suggest: Extract into a reusable API client
const getUser = (userId) => apiClient.get(`/users/${userId}`)

Security and Performance

• Are user inputs properly validated and sanitized?
• Could this code path cause performance issues at scale?
• Are secrets or sensitive data properly handled?

The Human Side

Celebrate Good Code

✅ "Nice use of the builder pattern here—very readable!"
✅ "This error handling is thorough and user-friendly"
✅ "Great test coverage on the edge cases"

Provide Context for Suggestions

Consider extracting this logic into a custom hook:

```tsx
function useLocalStorage(key, defaultValue) {
  // ... implementation
}

This would make it reusable across components and easier to test in isolation.

### Share Knowledge
Use reviews as teaching moments:
```markdown
TIL: You can use `Object.hasOwn()` instead of `obj.hasOwnProperty()` 
for better performance and to avoid prototype pollution issues.

Effective Review Techniques

The 3-Pass Review Method

1. First Pass: High-level architecture and approach
2. Second Pass: Logic, error handling, and edge cases
3. Third Pass: Style, naming, and documentation

Use Review Templates

## Checklist
- [ ] Code follows project conventions
- [ ] Tests cover new functionality
- [ ] Documentation updated if needed
- [ ] Security considerations addressed
- [ ] Performance impact considered

## Questions
1. How does this handle the case where...?
2. Could this approach scale to...?
3. What happens if...?

Tools and Automation

Automated Checks

Let tools handle the routine stuff:

# .github/workflows/pr-checks.yml
- name: Run linting
  run: npm run lint
  
- name: Run type checking  
  run: npm run type-check
  
- name: Run tests
  run: npm run test:ci

Review Assignment

# CODEOWNERS file
# Global reviewers
* @team-leads

# Frontend specific
/src/components/ @frontend-team
/src/styles/ @design-system-team

# Backend specific  
/api/ @backend-team
/database/ @backend-team @database-team

Common Anti-Patterns to Avoid

Nitpicking Style

If your linter and formatter are configured correctly, style shouldn't be a review topic.

Scope Creep

❌ "While you're here, can you also refactor the entire UserService?"
✅ "This looks good. For future work, consider refactoring UserService for better testability"

Blocking on Preferences

❌ "I prefer if/else over ternary operators"
✅ "This ternary is hard to read—could we use an if/else for clarity?"

Building a Review Culture

Set Clear Expectations

• Reviews should happen within 24 hours
• Provide specific, actionable feedback
• Explain the "why" behind suggestions
• Acknowledge good practices and clever solutions

Lead by Example

Senior developers should model good review behavior:

• Admit when you learn something from a junior developer's code
• Ask questions about approaches you're unfamiliar with
• Thank reviewers for catching your mistakes

The Bigger Picture

Code reviews are investments in your team's future. They:

• Spread knowledge across team members
• Maintain quality standards consistently
• Catch bugs before they reach production
• Build team culture through collaboration

When done well, code reviews make everyone better developers. The code gets better, the team gets stronger, and shipping becomes more confident.

Remember: You're not just reviewing code—you're building the future of your codebase and your team.

What makes a code review particularly helpful for you? Share your experiences with effective code review practices.