In our modern app we have C# on the iOS, Android, and Windows client apps, and the services and web server are built with C#. In this session you will learn how we leveraged the open source CSLA .NET framework to reuse nearly 100% of the business logic (written in C#) across all these different platforms and scenarios. If you are going to get high levels of business logic reuse you need clear separation of concerns, as well as help abstracting away various platform and runtime differences; and in this session you'll learn how to do exactly that in your apps.