It always sounds easy - "use the best tool for the job". With very isolated systems, it's easy to decide RDBMS for one application, Redis for another and Cassandra for somethings else. When it comes time to building systems with multiple persistent stores, we're met with challenges in integration, existing applications, and push back from IT administrators. In this session, we'll look at the multitude of challenges of achieving polyglot persistence nirvana, and strategies for addressing associated risks. We'll journey through an exploration of a working system that combines relational, key-value, document and graph databases without falling to its knees in complexity. With strategies like REST, messaging, service buses and compositional user interfaces, we'll find how amazingly complex websites like Amazon are within reach by us mere mortals.