Chapter 4, Domain Model and Asynchronous Events

1. The maintenance domain.
2. The primary reason for using the mediator pattern is to decouple the producing and consuming code, allowing for a specific object to manage communications and reducing dependencies that could couple those consumers and producers together. The sample application uses the INotification and INotificationHandler<T> interfaces to differentiate event handlers within the domains and allow for known actions to be taken when an event handler is invoked.
3. No – asynchronous programming, as seen with the async/await pattern in C#, does not automatically create new threads when an async method is called. New background threads can be spun up as a result of an async method when using Task.Run() or Task.Factory.StartNew() to create a new task.