Worked on enhancing the reliability of the Kolibri ClassroomNotifications API by addressing a critical bug that caused crashes during error-prone filtering operations. Focused on backend development using Python and Django, the approach involved fixing an UnboundLocalError in the ClassroomNotificationsViewset when a DatabaseError occurred, ensuring the application remained stable under failure conditions. Added a regression test to verify robust error handling and moved imports to align with project standards. These changes improved PostgreSQL CI stability and reduced the likelihood of user-facing crashes, contributing to a more dependable notifications endpoint within the learningequality/kolibri repository during the development period.