The roles and responsibilities of real time Salesforce administrator are

1. Setting up users.

2. Setting up Roles and Responsibilities.

3. Adding users to Queue, Public Groups, Chatter Groups, Permission Sets, etc…

4. Creating reports for data validation.

5. Loading new data.

6. Freezing and unfreezing users during Bulk Data Load, Sandbox refresh and multiple deployments.

7. Informing users before Sandbox refresh.