Complex sentence: Beginning his career in 2002, He joined "Emmerdale" in 2003 as a writer, he later went on to be an assistant producer and also a story editor on "Coronation Street".
Split into simpler sentences: Beginning his career in 2002, he joined "Emmerdale" in 2003 as a writer. He later went on to be an assistant producer and also a story editor on "Coronation Street".