The highest-level part of the design process is also the most exciting: designing the application architecture. In this stage, the application begins to come to life, without bogging you down in technical details. You create a logical design for your application and then map the logical layers to physical servers. Once you determine the physical layout, you can choose inter-application communication mechanisms to expose your business logic to different front-end user interfaces (UIs) and determine your authentication, authorization, and cryptographic requirements.

Further into the design process, you choose whether you need to support Component Object Model (COM) interoperability, and what changes you might need to make to provide that as efficiently as possible. You also will need to plan for scalability by estimating the minimum and maximum processing requirements of your application, how those requirements might change over its lifespan, and how you can scale the application accommodate it. Finally, you will need to decide how to use globalization and localization to adapt your application for different locations and languages. You must format data correctly for different regions and provide UI elements in the user’s preferred language.