This document discusses Rakuten Card's migration of its core credit card processing systems from an aging mainframe architecture to a new architecture based on Oracle Exadata, Exalogic, and Oracle Cloud Machine. The migration involved converting terabytes of data from legacy formats to Oracle Database, reimplementing software from Japanese COBOL to Java EE, and deploying the new systems with no downtime or issues. The new standardized architecture provides improved performance, scalability, portability, and security compared to the old vendor-locked mainframe systems. Overall the migration was completed on schedule and the new systems have been successfully operating in production.