@Kaniz Fatma​ @Parker Temple​  I found an root cause its because of serialization. we are using UDF to drive an column on dataframe, when we are trying to load data into delta table or write data into parquet file we are facing  serialization issue . Can you please help to provide best way to create UDFs or an alternate way for UDF in Scala where its should be have an return type (with some example).