When we start on our quest in creating a solution that solves what business wants from us, it is our best intent to come up with a simple system. And sometimes, we are blinded by the simplicity of the code itself in calling these "services" in a synchronous fashion. But by doing so, we unintentionally mask the availability concern. Yes, calling a service with three lines of code is indeed simple looking and easy. But, it hides a lot of What-ifs. What if the service is not up? What if the client called the method and the service operation is executing and the operation timed out on the client side, but the operation completed on the server side? What if this was a web service in a land far far away? Should we need to retry the failed operation? Can we safely retry the operation? And this brings us to the land of temporal coupling. In this session, we'll take a deep dive into what makes the systems we write reliable and how to address the classic temporal coupling problem. We'll see how classic Event Driven Architecture and messaging helps address this and build a reliable bus based system using NServiceBus all in a matter of 60 minutes.