Complex sentence: Jonathan was editor of the National Theatre's "StageWrite" magazine from 1992 to 2007, and has also edited "Arts Express" magazine, and worked as the programmes editor at the Old Vic.
Split into simpler sentences: Jonathan was editor of the National Theatre's "StageWrite" magazine from 1992 to 2007. He has also edited "Arts Express" magazine, and worked as the programmes editor at the Old Vic.