During April 2026, Diogo Pan focused on enhancing reliability in the gopidesupavan/airflow repository by addressing a bug in Airflow’s ExternalTaskSensor for versions below 3.0. He improved the existence check logic in deferrable mode, ensuring that the sensor correctly raises an ExternalDagNotFound error when a target DAG is missing. This work involved updating error handling, adding regression tests to validate the new behavior, and revising documentation to clarify the temporary nature of the fix. Diogo’s contributions, using Python and backend development skills with a focus on testing, strengthened cross-DAG task dependency robustness and prepared for future Airflow upgrades.