Which principle is NOT part of Sitecore's Helix design guidelines?

The correct answer is related to the principle that does not align with Sitecore's Helix design guidelines. Helix emphasizes modular architecture, separation of concerns, and adherence to SOLID principles as key components to create maintainable and scalable solutions within Sitecore projects.

The modular architecture principle ensures that the application is divided into smaller, manageable, and independent modules, which can be developed, tested, and deployed separately. This approach promotes reusability and a clearer structure.

Separation of concerns directs developers to organize code in a way that allows different aspects of functionality to be managed independently. This is crucial for managing complexity and ensuring that components can be modified without unintended consequences on unrelated parts.

Adherence to SOLID principles involves implementing a set of object-oriented design principles intended to make software designs more understandable, flexible, and maintainable. These principles guide developers in creating a robust architecture that is easy to adapt over time.

The centralized database model, however, is not a guiding principle of Helix. Helix encourages flexibility in how content and data are managed, and this may involve disparate sources rather than relying on a single, centralized database structure. Thus, this principle does not fit within the framework established by Helix design guidelines.