Assistant coaching roles Sitake got his start as an assistant coach during the 2001 season when he worked as the
defensive backs coach and
special teams coordinator at
Eastern Arizona College. In 2002, he returned to his alma mater, BYU, as a graduate assistant for the defense. From 2003 to 2004, he worked at
Southern Utah University. During the 2003 season, he was the
running backs and
tight ends coach; he coached the
offensive line and
tight ends during the 2004 season. Sitake's tenure at the U of U started in 2005, where he coached the
linebackers, until being promoted to
defensive coordinator on December 7, 2008. His formal duties began on January 3, 2009. Sitake became the first native Tongan named as a defensive coordinator at an NCAA
FBS school, following the resignation of the previous defensive coordinator,
Gary Andersen. On December 23, 2014, OSU announced Sitake's hiring as the team's new defensive coordinator and assistant head coach. This reunited Sitake with OSU's head coach, Andersen, whom Sitake had previously worked with at the U of U.
Head coach at BYU On December 19, 2015, after
Bronco Mendenhall left BYU to coach the
Virginia Cavaliers, BYU named Sitake as the team's new head coach. On September 3, 2016, Sitake's head coaching career began with BYU facing Arizona in the Cactus Kickoff in University of Phoenix Stadium in Glendale, AZ. The Cougars won, 18–16. BYU then lost three games in a row, for a 1–3 start. They then won four games in a row, including a road victory at
Michigan State and a homecoming win against
Mississippi State. Sitake eventually finished his first season 9–4, leading BYU to a 12th consecutive bowl game. The four losses were by a combined eight points. Expectations were high for BYU heading into the 2017 season, despite the loss of many graduating seniors, including starting quarterback
Taysom Hill and running back
Jamaal Williams. The loss of offensive production proved to be detrimental, as the Cougars had their worst season in over 50 years, starting 1–7 before slogging to a 4–9 finish. After the season, Sitake fired offensive coordinator
Ty Detmer due to the offense not delivering satisfactory production. He hired
Jeff Grimes to replace Detmer. The 2018 season was a slight improvement over the previous year. It was defined by inconsistent success, with the highlight of the year being an upset victory over No. 6-ranked
Wisconsin. However, the team continued to struggle, with an especially tough loss to Northern Illinois at home and blowing a 20-point lead at archrival the U of U. Despite the lack of consistency for much of the season, a few silver linings were present. Sitake benched starting quarterback
Tanner Mangum in favor of true freshman
Zach Wilson. With Wilson at quarterback, the team won five of its final seven games to improve to 7–6, including a 49–18 win over Western Michigan in the
Famous Idaho Potato Bowl, noted for Wilson's perfect passing performance (18-for-18, 317 yards, and 4 touchdowns). Sitake's fourth season with the team restored higher expectations for the Cougars even with their first four games being against tough competition. BYU initially had success with upset wins over
Power Five programs such as
Tennessee and a ranked
USC team, but inconsistency returned. Wilson regressed heavily, due to struggling to remain healthy, and missed five games due to a broken thumb. 2019 was defined by the depth at the quarterback position, though, as backups
Jaren Hall and
Baylor Romney both led BYU to wins late in the season to help get the team to the
Hawai'i Bowl against the
University of Hawaiʻi. However, they lost that game 38–34 in which Wilson returned and delivered mixed results. The team's final record was the same as the previous season's at 7–6. Sitake received a contract extension from athletic director
Tom Holmoe through the 2023 season. Going into his fifth season coaching the team, many questions lingered, such as the ability to deliver consistent success. The offseason began with a highly anticipated competition for the starting quarterback position between Wilson, Hall, and Romney. However, football operations were halted when nationwide lockdowns were implemented due to the
COVID-19 pandemic. BYU was set to face another tough schedule, with opponents such as the U of U, Michigan State, Arizona State, Minnesota, Missouri, and Stanford. All these games were cancelled due to the Power Five conferences largely opting to restrict games to within their leagues, leaving the Cougars with only three games. Holmoe gradually re-built the season by adding several teams on short notice, allowing the Cougars to play as many games as possible. Wilson won back the starting job, and successfully Sitake guided the team through the revamped schedule. The Cougars finished the 2020 season with an 11–1 record, defined by Wilson's resurgence in production. The team finished with a No. 11 national ranking in both the
AP Top 25 poll and the Amway
Coaches' Poll, their highest final ranking since 1996. It was also the team's first 11-game winning season since 2009, and their first one-loss season since 1996. Several players on the team, including Wilson, opted to forego their senior seasons and declare for the
NFL draft. Offensive coordinator Jeff Grimes departed BYU after the season, taking offensive line coach Eric Mateos with him to
Baylor. Sitake promoted quarterbacks coach
Aaron Roderick to replace Grimes. In his sixth season as head coach at BYU, Sitake replaced Wilson with starting quarterback Jaren Hall. Following a 24–16 win against Arizona, BYU faced the U of U for the first time since 2019. BYU entered the game as a 7-point underdog. However, BYU won the game 26–17 and ended the Utes' 9-win streak against the Cougars with a strong defensive and offensive dominance. He was inducted into the Polynesian Football Hall of Fame on January 18, 2025 at the Polynesian Cultural Center in Laie, Hawaii. ==Personal life==