performance-optimizerlisted

# Performance Optimizer Auto-detects and fixes Django ORM performance issues before they reach production. ## Activation Triggers This skill activates when: - Writing ORM queries - Accessing related objects (foreign keys, M2M) - Creating views that fetch data - Mentioning "slow", "performance", "optimization" - Looping over querysets - Creating list/detail views ## Performance Targets - ✅ NO N+1 queries - ✅ Appropriate indexes on frequently queried fields - ✅ Pagination for list endpoints - ✅ `select_related()` for foreign keys - ✅ `prefetch_related()` for reverse foreign keys and M2M - ✅ Caching for expensive operations ## Auto-Detection Patterns ### Pattern 1: N+1 Query Detection **❌ INEFFICIENT (N+1 query):** ```python # Bad: 1 query for users + N queries for organizations users = User.objects.all() # 1 query for user in users: # N queries print(user.organization.name) # Hits DB each time! ``` **✅ OPTIMIZED:** ```python # Good: 2 queries total (1 for users + 1 JOIN for organizations) users = User.objects.select_related('organization').all() for user in users: print(user.organization.name) # No DB hit! ``` ### Pattern 2: Reverse Foreign Key N+1 **❌ INEFFICIENT:** ```python # Bad: 1 + N queries organizations = Organization.objects.all() # 1 query for org in organizations: # N queries users = org.users.all() # Hits DB each time! print(f"{org.name}: {users.count()} users") ``` **✅ OPTIMIZED:** ```python # Good: 2 queries total organizations =