He is best known for his work on Rooster Teeth's machinima series Red vs. Blue, for which he wrote the story; he also provided voice work for the character Church among several others. He remains intimately involved in many Rooster Teeth productions, hosting the internet game show The Gauntlet and the reality series Immersion, as well as starring in the feature film Lazer Team. He also regularly appears on the Rooster Teeth Podcast.
He is married to Rooster Teeth employee Ashley Burns, who voices Coco Adel in RWBY. The couple appeared together on Season 28 of the CBS reality television show The Amazing Race, which was nominated for an Emmy Award.
On September 26, 2019, Burnie stepped down from his position as CCO along with regular work with the company, transitioning to a producer role in the newly formed Rooster Teeth Studios division, reporting to Ryan Hall. In addition, he announced that September 30, 2019 would be his final regular appearance on the Rooster Teeth Podcast.
Later, Burnie left Rooster Teeth after planning to leave for a while. However, he remains on friendly terms with the company and still voices Church and Taiyang.
- Burnie appeared, animated in the style of an RTAA, in the Animated RT Recap alongside an RTAA version of Joel Heyman, Gus Sorola and various characters from Red vs. Blue and RWBY.
- Burnie is very invested in voicing Taiyang and takes it very seriously. He would go over the script with Miles Luna and Kerry Shawcross before recording sessions and Burnie will listen to Yang Xiao Long's lines and efforts and try and make Taiyang's similar as a way of representing how Yang was influenced by her father.
- Volume 4 Directors' Commentary Chapter 4