Ross came to notice in the mid-1990s as a programmer for Tim Simenon's Bomb the Bass during the period of the albums Unknown Territory and Clear. He worked on a number of production and remix projects with Simenon, as well as forming a collaborative relationship with Barry Adamson. He programmed The Negro Inside Me and Oedipus Schmoedipus, and produced As Above So Below before forming his own band, 12 Rounds, with Claudia Sarne and Adam Holden. They released two albums, Jitterjuice and My Big Hero. A third full-length album was produced by Trent Reznor, but was ultimately never finished. Three songs from that album have since been released on the band's website.
Since moving to the United States in 2000, Ross has been credited as a Producer and/or programmer on the Nine Inch Nails albums With Teeth, Year Zero, Ghosts I-IV (on which he was a co-writer), The Slip, and Hesitation Marks. He performed live with the band at the Wiltern. Beyond Nine Inch Nails, he has worked with Trent Reznor on other acts, including Saul Williams and Zack de la Rocha, and they co-produced tracks for a reformed Jane's Addiction with Alan Moulder in 2009.
On 1 July 2010, Trent Reznor announced that he and Ross were scoring David Fincher's new film The Social Network. The Soundtrack was released on 28 September 2010 and was highly praised. On 16 January 2011, they won the award for Best Original Score at the 68th Golden Globe Awards for their score to The Social Network. On 27 February, they received the Academy Award Best Original Score for The Social Network. Ross and Reznor again collaborated on the Soundtrack to Fincher's 2011 film Girl With the Dragon Tattoo. In 2013, the pair won a Grammy Award for Best score Soundtrack for visual media for their Girl with the Dragon Tattoo Soundtrack.
Ross was slated to work on the 2013 samurai epic 47 Ronin, directed by Carl Rinsch, but was soon replaced by Javier Navarrete. Ross and Reznor again teamed up with Fincher to score his 2014 film Gone Girl. In 2016, Ross and Reznor, along with Composer Gustavo Santaolalla and the band Mogwai, collaborated to create the score to the documentary film Before the Flood.
On 25 June 2017 Ross, along with Trent Reznor, Mariqueen Maandig Reznor, Robin Finck, Joey Castillo, and Alessandro Cortini appeared as "The Nine Inch Nails" in Episode 8 of Twin Peaks: The Return on Showtime, performing an alternate live rendition of the song "She's Gone Away" which previously appeared on Nine Inch Nails' 2016 extended play Not the Actual Events.
