Final answer:
An Autonomous Database does not perform application development by default. It manages tasks like tuning, patching, and updating, but building and maintaining applications still require developers.
Step-by-step explanation:
The task that is NOT performed by default by an Autonomous Database is application development. An Autonomous Database automatically handles many tasks that traditionally required DBA intervention, such as tuning, patching, updating, and backing up the database. While it greatly reduces the operational overhead, it does not replace the need for developers to build and maintain the applications that will connect to the database. Therefore, activities such as developing application logic, designing user interfaces, or implementing application-level security are not within the scope of the services provided by an Autonomous Database.