## 1. Query Analysis
- [x] 1.1 Enable SQLAlchemy query logging in development
- [x] 1.2 Identify all N+1 query patterns
- [x] 1.3 Document current query counts per endpoint

## 2. Optimization Implementation
- [x] 2.1 Add joinedload for project member relationships
- [x] 2.2 Add selectinload for task assignee relationships
- [x] 2.3 Implement batch loading for user details
- [x] 2.4 Add appropriate indexes if missing

## 3. Verification
- [x] 3.1 Benchmark before/after query counts
- [x] 3.2 Write performance regression tests
- [x] 3.3 Document optimization patterns for future reference

---

## Implementation Summary

### Changes Made

1. **Query Monitoring Module** (`app/core/query_monitor.py`)
   - Added `QueryCounter` context manager for counting queries per request
   - Integrated SQLAlchemy event listeners for query logging
   - Added threshold-based warnings when query count exceeds limit
   - Configurable via `QUERY_LOGGING` and `QUERY_COUNT_THRESHOLD` settings

2. **Configuration Updates** (`app/core/config.py`)
   - Added `DEBUG`, `QUERY_LOGGING`, `QUERY_COUNT_THRESHOLD` settings

3. **Project Router Optimizations** (`app/api/projects/router.py`)
   - `list_projects_in_space`: Added `joinedload` for owner, space, department; `selectinload` for tasks
   - `list_project_members`: Added `joinedload` for user (with department) and added_by_user

4. **Task Router Optimizations** (`app/api/tasks/router.py`)
   - `list_tasks`: Added `selectinload` for assignee, status, creator, subtasks, custom_values
   - `list_subtasks`: Added `selectinload` for assignee, status, creator, subtasks

5. **Performance Tests** (`tests/test_query_performance.py`)
   - Test cases for project member list optimization
   - Test cases for project list optimization
   - Test cases for task list optimization
   - Test cases for subtask list optimization

### Query Count Improvements

| Endpoint | Before (N members/tasks) | After |
|----------|-------------------------|-------|
| `/api/projects/{id}/members` | 1 + 2N queries | 2-3 queries |
| `/api/spaces/{id}/projects` | 1 + 4N queries | 4-5 queries |
| `/api/projects/{id}/tasks` | 1 + 4N queries | 5-6 queries |
| `/api/tasks/{id}/subtasks` | 1 + 4N queries | 4-5 queries |