I appreciate the approach you've taken with the Saga Pattern to manage distributed transactions and ensure financial integrity within Baraza SACCO. However, I see a significant concern with your reliance on AWS Step Functions as the orchestrator. While they provide a robust solution for managing workflows, they can introduce latency and complexity, especially when handling high volumes of concurrent requests typical in mobile money environments. If the orchestrator encounters performance bottlenecks or failures, it could lead to delayed compensating transactions, risking money loss during peak times. Additionally, the use of multiple Lambda functions for the ledger and compensating transactions raises concerns about monitoring and debugging. Each function's failure could cascade and complicate the debugging process. Ensure you have comprehensive logging and monitoring in place, particularly for payment failures through the dead-letter queue (DLQ) and alert alerts via SNS. Lastly, consider the implications of idempotency in your design. While it helps prevent duplicate transactions, there should be a clear strategy for handling scenarios where an operation might be retried multiple times, risking inconsistent state. Addressing these issues will enhance the overall robustness of your architecture.