The document discusses how a large international reservation system deployed Terracotta's BigMemory to reduce mainframe usage and costs. As a result of the deployment, the system saw a 80% reduction in daily mainframe transactions, 50% faster response times, a 20x increase in capacity, and maintained 99.99% uptime. The system was facing challenges of expanding capacity to support growing traffic while reducing costs. BigMemory provided an in-memory data layer on commodity hardware that replaced the mainframe for over 99% of transactions.