Ruiz was born on January 15, 1998, in Reno, Nevada. He attended Bishop Manogue Catholic High School, where he was a three-sport star in football, basketball, and track. In football, Ruiz was named to the All-State team as a senior.
After high school, Ruiz committed to Michigan. He redshirted his first season in 2017. In 2018, he became a full-time starter at left guard for Michigan. He started all 13 games and earned second-team All-Big Ten honors. In 2019, Ruiz started all 13 games again and was named a unanimous first-team All-Big Ten selection.
Ruiz declared for the 2020 NFL Draft after his junior season. He was drafted with the 24th overall pick by the New Orleans Saints. He started all 16 games as a rookie in 2021 at center.
Ruiz is the son of Mexican immigrants. He is the first person of Mexican descent to start at center for Michigan.