Analyze the code for performance optimization opportunities. Focus on:

1. **Algorithm Efficiency**
   - Time complexity analysis
   - Space complexity analysis
   - Suggest more efficient algorithms

2. **Database Optimization**
   - Query optimization
   - Index recommendations
   - N+1 query problems
   - Caching opportunities

3. **Memory Management**
   - Memory leaks
   - Unnecessary object creation
   - Resource cleanup

4. **Code Structure**
   - Redundant computations
   - Unnecessary loops or iterations
   - Lazy loading opportunities

5. **Network/IO Operations**
   - Batch operations
   - Connection pooling
   - Async/await optimization

6. **Caching Strategy**
   - What should be cached
   - Cache invalidation strategy
   - Memory vs performance tradeoffs

Provide specific refactoring suggestions with before/after code examples showing the performance improvements.