Doug's television debut was at kids television series Clarissa Explains It All on Nikelodeon in 1991.
Doug has written the scripts of some Buffy the Vampire Slayer comic books.
Throughout his time as part of the Buffy crew, he worked as co-executive producer, executive story editor, writer and director.
Doug has stated that the vampire Sunday, who appeared in only one epsiode of Buffy the Vampire Slayer is one of his all time favorite characters of the series.
Doug has stated that he and his fellow writers of Buffy the Vampire Slayer saw Season 4 of the series as a completely new show, with all the changes.
Doug, like many other television writers, love to surprise viewers, and he once stated that he loves to visit forums to see the fans' reactions to his work.
Doug is a big James Bond fan.
Before starting his work as a writer on television series Buffy the Vampire Slayer, Doug had only worked with movies.
Doug has on several occasions during commentary tracks on the DVD editions of a few episodes of Buffy the Vampire Slayer, said that he would like his name to appear in the credits, in huge neon letters, jumping all over the screen.
In the Angel episode "Why We Fight", Angel is summoned by Commander Petrie from a military organisation named "Demon Research Initiative", as an in-joke reference to Doug.
Doug wrote an early draft of the superhero movie "The Fantastic Four".
Doug (About having a gay character on Buffy the Vampire Slayer): Then the gay and lesbian community was very vocal about, "You must do this and you must not do that," and we're again kind of saying, "Listen, we're never going to be homophobic on this show but at the same time we are telling a story and we are storytellers, and we have the right to tell our story the way we want to." We don't want to be pressured from the left or the right to have people say "well for personal and political reasons you must do this with the story" or "you must do that for the story." But you know what? We're telling the story.
Doug: Joss came up with the idea that, everything we can't explain – "Blame it on Spike!". We all loved that! It was very satisfying and very funny. So that's kind of how we dealt with that. In general we do literally have a big whiteboard in Joss's office but not everything is written down. Joss Whedon's cranium is the resting place for a lot of the ideas.
Doug (About writing for both Buffy and Angel): Angel is a very cool world and a very different world but it is a pretty big gear shift and I think some of us are better at it than others - but it's a great place to visit.
Doug: People say 'Executive Story Editor', and I say Is that what I am? I can never remember what the titles are! I think the titles don't mean a lot and I never keep them straight. I think now, in season five, I'm a co-producer.