Hollier previously worked as a writer and producer on various shows including The Originals, Once Upon a Time, and Elementary. He knows showrunner Carina Adly MacKenzie from working with her on The Originals.
When MacKenzie was developing the show, she chose Hollier to be her co-showrunner. Hollier had shown that he respected and supported her when they worked together on The Originals. One of the reasons she hired him is because she knew she needed to work with a man to deal with any misogyny that might come up, and he wouldn't let people try to go over her head to him. She describes Hollier as being "absolutely fucking brilliant, and so talented, and so kind, and so fucking fun to have a drink with" and "just the fucking best."
Hollier is a writer for the following Roswell, New Mexico episodes:
Julie Plec:"What is it about this show that you think men can connect to? Like you, a sensitive soul like yourself?"
Hollier:"Not only is the cool sci-fi gadgetry stuff that you just talked about, but I can't think of anything more manly than standing up and saying, "I love this woman" or "I love this man." And to me, that is the cornerstone of all storytelling. In the writers room from day one, I said, my favorite story point, beyond all the sci-fi stuff, is when someone interrupts another person dancing with somebody else. That's all I'm really here to do."
Carina Adly MacKenzie:"He loves an interrupted dance and he loves "I just know by looking in your eyes.""
Hollier:""I just know!""
MacKenzie:"And I'm always like, "That doesn't happen in real life!""
Hollier:"You look at them kissing on that hill, they both know in their eyes!"
MacKenzie:"By the way, you wouldn't guess this, but I'm the least romantic human that's ever lived. Hollier is the most."
Hollier:"This is our yin and yang quality."
— Crashdown on Sunset Experience panel, January 2019