ABSTRACT
The architecture of information technology (IT) systems evolved toward more and more separation of concerns among the components of the applications. The scope of the IT systems grew larger to also address interdepartmental interactions such as transfer of business data from one department in the enterprise to another—say from booking to finance in the case of a transportation company. Structured programming started becoming popular, though it was not uncommon to see unstructured programming in the enterprise applications. Being monolithic in nature, the architecture made the user interface, business logic, and data access parts all to be contained in a single application, and the application ran entirely in mainframe. The popularity of model-view-controller pattern-based architecture meant an architecture where the IT system was separated into top-level components based on their specific concerns. The level of abstraction in the architecture increased to handle the business process logic as distinct entities separately from other business components.
