Redis was used to improve performance for two game companies experiencing rapid growth. For Monster World, moving write-intensive inventory data to Redis reduced load on MySQL by 10% and allowed further data migration. For Happy Hospital, Redis served as the main database to handle peak loads of 4000 requests/second, achieving response times of 10ms. The main challenge was ensuring durability with Redis' virtual memory, but a diskstore solution currently in development was promising. Both cases found Redis provided order-of-magnitude performance improvements over their original architectures.