Financial systems must operate with a high degree of reliability. Even short periods of downtime or failure can result in significant financial loss, operational disruption, and loss of user trust. As modern systems move toward distributed microservices architectures, ensuring fault tolerance becomes both more challenging and more critical. Resilience patterns provide a structured approach to building systems that can handle failures gracefully while maintaining core functionality. This article explores key resilience patterns and how they can be applied to build fault-tolerant financial systems. The Challenge of Fault Tolerance Distributed systems introduce new types of failures: Network latency and communication failures Service unavailability Database bottlenecks Unexpected spikes in traffic In financial systems, these issues are amplified due to high transaction volumes and strict availability requirements. A failure in one service can cascade into multiple failures if not handled properly.…