Performance Optimization

Process

1. Identify hot paths — Which code runs most frequently or handles the most data?
2. Check algorithmic complexity — Look for O(n^2) or worse in loops, searches, sorts
3. Database query analysis:
   • N+1 queries (loop making individual queries instead of batch)
   • Missing indexes on WHERE/JOIN/ORDER BY columns
   • SELECT * when only specific columns needed
   • Unnecessary subqueries that could be JOINs
4. Caching opportunities:
   • Repeated expensive computations
   • Frequently read, rarely updated data
   • API responses that can be cached
5. Memory usage — Large objects in memory, memory leaks, unnecessary copies
6. I/O optimization — Batch operations, connection pooling, async I/O
7. Lazy loading — Defer expensive operations until actually needed

Output Format

## Performance Analysis: [Component/Module]

### Bottlenecks Found (Impact Order)

#### 1. [Bottleneck Title]
- **Location**: file:line
- **Type**: Algorithm / Database / Memory / I/O
- **Current**: O(n^2) nested loop over all users
- **Proposed**: Use a hash map for O(n) lookup
- **Expected Impact**: High / Medium / Low
- **Effort**: Small / Medium / Large

### Quick Wins
- [Changes that are easy to implement with high impact]

### Long-Term Improvements
- [Larger refactors for sustained performance gains]

### Metrics to Track
- [What to measure to verify improvements]

Guidelines

• Profile before optimizing — don't guess where bottlenecks are
• Fix the biggest bottleneck first (Amdahl's law)
• Prefer algorithmic improvements over micro-optimizations
• Consider caching only when data is read-heavy and stale data is acceptable
• Database indexes have write overhead — only add for proven query patterns
• Measure before and after every change
• Don't sacrifice readability for marginal performance gains