Design for Everything

The more code I write the complexity of what I want to do increases, and the number of design variables increase.  I find that I have to design for ...

• testing - code to interfaces that lend themselves to unit testing
• remote procedure call - remote APIs must be call by value
• security - keep JAAS in mind for authentication and access control
• user interaction - design APIs to provide hooks for user feedback, support user cancel requests, or implement the observable pattern to allow UI listeners for view changing events
• monitoring - logging, JMX, timers
• extensibility - OSGi implements a nice plugin architecture
• transactions - ability to rollback multipart operations on failure after partial processing
• cacheing - ability of client to cache data from server in a consistent way
• injection and late binding - I like GUICE for dependency injection, but am lately struggling with marrying the GUICE's preference for data binding at application startup with a UI design that allows runtime definition of injectable parameters.