What strategies can be used for effective test automation in a large-scale Python Django application?

For effective test automation in a large-scale Django application, focus on creating a comprehensive test suite covering unit, integration, and functional tests. Utilize Django's built-in testing framework for unit tests and tools like Selenium for functional tests. Also, implement a continuous integration (CI) pipeline to run tests automatically on code commits.

Remember to structure these tests modularly, primarily to reduce dependencies and improve maintainability. Emphasize test coverage, but avoid redundant tests. Finally, use mock objects and factories for database interactions to speed up testing and isolate test environments.