1. Schema changes: Move each entity on its own collection - each entity keeps ids for its sub-entities.2. New controllers for each entity: TopicController.java, CategoryController.java, SubCategoryController.java, IndicatorController.java.3. New DAOs for each entity: TopicDAO.java, MongoDBTopicDAO.java, CategoryDAO.java, MongoDBCategoryDAO.java, SubCategoryDAO.java, MongoDBSubCategoryDAO.java....