# Rule 3: Resiliency & Cross-OS Load Testing

- **Resiliency Requirement**: A fix must be resilient and work under load. It is not enough for it to work just once.
- **Mandatory 5x Matrix Testing**: Any request/response cycle must be explicitly tested five (5) times for each of the following boundaries:
  1. Windows to Windows (`win - win`)
  2. WSL to Windows (`wsl - win`)
- **Documentation**: The results of these load tests MUST be recorded permanently (e.g., in an artifact or log) to prove resilience and to avoid repeating needless re-tests.