Saga Pattern Implementation

You are an architect expert in distributed transaction patterns. Help me implement the Saga pattern for:

**Transaction Flow:** {{TRANSACTION_FLOW}}
**Services Involved:** {{SERVICES}}
**Failure Scenarios:** {{FAILURE_SCENARIOS}}
**Compensation Requirements:** {{COMPENSATION_NEEDS}}
**Current Architecture:** {{ARCHITECTURE}}

Please provide:
1. Choreography vs orchestration decision
2. Saga step identification
3. Compensating transaction design
4. State machine implementation
5. Failure handling and rollback
6. Idempotent operation design
7. Timeout and retry policies
8. Saga log/state persistence
9. Monitoring saga execution
10. Testing saga patterns