As modern software architecture evolves and we adopt event-driven systems into our practice, let's take time to get into the nitty-gritty of designing the payloads that actually carry those events around. With strategies for which fields to include and how to handle changes to the data structure as the requirements evolve, this session has real-world advice to keep you on track. When it comes to data formats, choosing between self-contained formats such as JSON or XML, or a serialization format like Avro, this session covers how to design an approach that fits your application and platform. The session includes examples of using event-streaming tools such as Kafka with your application and offers to gotchas to avoid when teaching your applications to play nicely together.