In Fautanu's first season in 2019 he redshirted and did not appear in any games. During the 2020 season, Fautanu appeared in four games.[5] During the 2021 season, Fautanu would play in nine games, starting in three of them.[6] Fautanu had a breakout 2022 season, where he started all 13 games.[7] In week three of the 2022 season versus Michigan State, Fautanu was named the Pac-12 offensive lineman of the week.[8] For his performance in the season, Fautanu was named second-team all Pac-12.[9] In the 2023 season, he won the Morris Trophy as the top offensive lineman in the Pac-12 and the Joe Moore Award as the top offensive line unit.[10] Following the season, he declared for the 2024 NFL draft.[11]
Fautanu was selected by the Pittsburgh Steelers with the 20th overall pick in the 2024 NFL draft.[14] He signed his four year rookie deal on June 3, 2024.[15] During the Steelers' preseason game against the Houston Texans, Fautanu sustained a knee injury, causing him to miss the remainder of the team's preseason.[16] He would not appear in Week 1, however, he would earn his first professional start the following week in a 13-6 victory over the Denver Broncos.[17] In his first start he allowed no sacks, committed no penalties and allowed no pressures as he played for 55 offensive snaps.[18]
On September 20, Fautanu left the Steelers' practice with an injury that required him to have an MRI. He was relieved by Broderick Jones at the right tackle position for the remainder of the practice ahead of the team's Week 3 game against the Los Angeles Chargers.[19]