With Virginia, he posted a stellar 50% FG, 42% 3FG, 90% FT shooting season, but came up just .004 short in free throw percentage from officially qualifying for the 50–40–90 club.

[5] He led his team to a 27–1 record and the Wisconsin Interscholastic Athletic Association Division 1 state championship, scoring 25 points in the title game against Germantown High School.

[6] As a senior, Hauser helped SPASH achieve an undefeated season and win a second consecutive Division 1 state championship.

[8][9] Hauser committed to playing college basketball for Marquette on May 17, 2015, over offers from Virginia, Iowa State and Creighton, among several other NCAA Division I programs.

[14] On February 21, 2017, Hauser matched his season high again, contributing 19 points with 5 three-pointers, 8 rebounds and 4 steals in a 93–71 victory over St. John's.

[24] On May 28, 2019, Hauser committed to continue his career at Virginia and sat out the next season due to National Collegiate Athletic Association (NCAA) transfer rules.

[27] With Virginia, he posted a 50% FG, 42% 3FG, 90% FT shooting season, but came up just .004 short in free throw percentage from officially joining the 50–40–90 club.

[30] On February 14, 2023, against the Milwaukee Bucks, he hit a game-tying three-pointer with three seconds left in the game, eventually sending it to overtime where the Celtics lost 131–125.

[35] Hauser helped the Celtics win the 2024 NBA Finals where they defeated the Dallas Mavericks in 5 games, contributing a total of 11 three-pointers throughout the series.