Architecture

• Application – layers – what do the layers do
• Where do the different components live
• Whats the interface between layers

Design principles

• Symptoms of bad design – rigid, fragile, easier to modify with hacks (viscosity)
• SOLID – employed by frameworks

Design patterns

• Used in frameworks – a lot employ the factory pattern
• May be used ourselves, iterator pattern?
• Singleton?

On tuesday we need a diagram of the application structure.