Where in the project structure is the data interaction layer located?

The data access layer is usually placed in a separate package or module, often called repository or storage. This layer is responsible for abstracting data access and isolating business logic from the details of working with a specific DBMS.

In the project structure, it is located below the service layer (business logic) and above the driver layer or external libraries for database interaction.

Example structure:

/project
  /cmd
  /internal
    /service  # business logic
    /repository  # database operations
    /models  # data structures
  /pkg

This approach facilitates testing and code maintenance, allowing changes to data access implementation without affecting the rest of the application.