In which type of extensibility are the extensions loosely coupled?

Side-by-side extensibility is characterized by the creation of extensions that are loosely coupled to the core SAP S/4HANA system. This approach allows developers to build applications outside the SAP environment, utilizing cloud platforms or other technologies without affecting the core system's integrity.

Such a configuration supports a microservices architecture, enabling functionalities to be developed and deployed independently. This decoupling enhances flexibility, scalability, and maintainability, allowing organizations to innovate more rapidly and adapt to changing business requirements without being restricted by the core system's updates or changes.

In contrast, the other types of extensibility tend to be more tightly integrated with the core system. Developer extensibility and key user extensibility are generally focused on making adjustments or enhancements within the framework or capabilities provided by the SAP system itself, which can result in stronger dependencies between the extensions and the core application. Classic extensibility often involves direct modifications to the existing application, which can lead to significant coupling and potential issues during upgrades or maintenance.