a real world point of view
Catrin Lewis Defis has been involved with television production at BBC Wales since at least 1997. Prior to the arrival of Russell T Davies in Cardiff in 2004, she had already been a line producer on a number of productions, such as Iechyd Da, The Shoe Collector, The Hairy Fairy and Con Passionate — some of which were Welsh-language programs.
Based on her track record, she was given significant responsibilities on Torchwood. During the first series, she was a production manager. In the second, she was elevated to the position of associate producer. Following the departure of Phil Collinson from Doctor Who, she was the full producer of TV: Music of the Spheres. In so doing, she became only the third woman to (line) produce an episode of Doctor Who, behind Verity Lambert and Susie Liggat.