How are checkout flows typically customized in SFCC?

Customizing checkout flows in Salesforce Commerce Cloud (SFCC) typically involves extending the default checkout controllers and views because this approach allows developers to build upon the existing framework rather than starting from scratch. By extending the controllers, you can implement custom business logic, add validation, and manage data flow in a way that aligns with specific business needs while maintaining the overall architecture of SFCC.

Manipulating the default views allows for alterations in the presentation of the checkout process, ensuring a consistent user experience while still incorporating any required customizations such as additional fields, changes in layout, or new functionalities based on business requirements. This method integrates seamlessly with SFCC's robust architecture, leveraging existing functionalities while providing the flexibility needed for customization.

Other methods, such as altering front-end styles directly, focus more on aesthetics than functionality, which can lead to a disconnect between user interface and backend processing. Creating separate checkout pages may complicate maintenance and lead to inconsistencies across different flows. Modifying user permissions doesn't directly impact the checkout flow customization; instead, it regulates access levels, which is outside the scope of what’s needed for altering the checkout process itself. Thus, extending the default checkout controllers and views is the most effective and structured way to customize the checkout experience in SFCC.