Composite application integration creates what appears to be a single application, purpose-built from the ground up to address user requirements. But if examining the deployment of the application, you will find components, both business logic and data, that are a part of existing production applications.
Initially, these integration patterns were applied for internal, application-to-application (A2A) integration and for integrating an organization's applications with those of its trading partners — that is, B2B integration. Today, the patterns are applied to a broader array of application integration projects:
Synchronizing data in software as a service (SaaS) applications with on-premises applications (for example, synchronizing customer data in a cloud-based CRM application with customer information in an on-premises ERP system