# PR Performance Check Gate
## Purpose
This gate identifies potential performance issues in code changes. It warns but does not block merge (advisory).
## What to Check
### Algorithmic Complexity
- O(n²) or worse nested loops
- Repeated database queries in loops (N+1 problem)
- Large array operations without pagination
### React/Frontend Specific
- Missing memoization for expensive computations
- Unnecessary re-renders from object/array literals in JSX
- Large bundle additions (new dependencies)
### Backend Specific
- Blocking operations on main thread
- Missing indexes for queried fields
- Unbounded queries without LIMIT
### General
- Debug statements left in code (console.log, debugger)
- Synchronous file I/O in request handlers
- Missing caching for repeated expensive operations
## Pass Criteria
- No O(n²) loops without documented justification
- Async operations for I/O
- Memoization for expensive pure functions
- No debug statements in production code
## Advisory Response Format
When this gate flags issues, provide:
1. **Issue type** (complexity, memory, I/O)
2. **Location** (file:line)
3. **Impact** (estimated severity)
4. **Suggestion** (optimization approach)
Example:
```
GATE ADVISORY - Performance concern detected
Issue: O(n²) nested loop
Location: src/utils/search.ts:23
Impact: Medium - may cause slowdown with large datasets (>1000 items)
Suggestion: Consider using a Map for O(1) lookups instead of inner find()
```
Note: This is advisory only. The chain will continue even if this check fails.
