The application DBA focuses on database design and the ongoing support and administration of databases for a specific application or applications. The application DBA is likely to be an expert at writing and debugging complex SQL and understands the best ways to incorporate database requests into application programs. The application DBA must also be capable of performing database change management, performance tuning, and most of the other roles of the DBA.
 
Application DBA responsibilities:   (Mandatory) 
1.       Implement and maintain the database design    
2.       Create database objects (tables, indexes, etc.)    
3.       Write database procedures, functions and triggers    
4.       Assist developers with database activities    
5.       Regular Performance Tuning of  database queries , procedures, jobs
6.       Monitor application related jobs and data replication activities
7.       Expert level skills to identify and troubleshoot production issue