Which architecture is best for Flutter?

The repository package introduces a bottom-up high-level data management abstraction layer that lets you do just that! There are only a few key concepts: Repositories can store objects. Objects which are stored in repositories are called items.

The Repository pattern. Repositories are classes or components that encapsulate the logic required to access data sources . They centralize common data access functionality, providing better maintainability and decoupling the infrastructure or technology used to access databases from the domain model layer.