Aranda graduated from Redlands High School in 1994. Aranda was also the roommate of Tom Herman in college at California Lutheran.
In 2012, Aranda was the Defensive Coordinator for one year for or the Utah State Aggies under Gary Andersen. That same year Aranda was a nominee for the Broyles Award as the Aggies defense finished in the top 15 of all FBS schools in all four major defensive categories; seventh in scoring defense (15.4 points per game), 13th in rushing defense (113.8 yards per game), eighth in pass-efficiency defense (14 interceptions, 12 touchdowns, 54.1% completion rate, 5.7 yards per attempt) and 14th in total defense (322.1 ypg).
When Gary Andersen was hired as the new Wisconsin Badgers head coach, following the 2012 football season, Aranda followed him to Wisconsin. Aranda turned down offers from Texas Tech and California. Aranda changed the Badgers' base defense from a 4–3 to a 3–4 and developed a more aggressive defense, putting pressure on the quarterback. His first year as Defensive Coordinator the Badgers defense ranked in the top 20 in all four major defensive categories; scoring defense (6th), total defense (7th), rushing defense (5th) and passing defense (17th).
Week 10 of the 2014 football season Aranda was named Coordinator of the Week by Athlon Sports after his Wisconsin Badgers defense shutout Rutgers Scarlet Knights 37–0. It was Wisconsin's first road shutout since 1998. The Badgers took 1st place in the West Division with a 10–2 record, going 7–1 in the conference. Wisconsin played Ohio State for the conference title in the 2014 Big Ten Championship Game where the Badgers lost to Ohio State 59–0. It was the first time since 1997 that the Badgers were shutout and the worst loss since 1979 when Ohio State also defeated the Badgers 59–0.
Four days after the Badgers lost to Ohio State, Gary Andersen departed Wisconsin for Oregon State. Former Badgers offensive coordinator (2005-2011) and Pitt head coach (2012-2014), Paul Chryst, was hired as the next head coach of the Badgers. Aranda was the only assistant coach to remain on the coaching staff after Andersen's departure.
Two of Aranda's three years at Wisconsin one of his linebackers won the Big Ten Linebacker of the Year, Chris Borland in 2013 and Joe Schobert in 2015. Borland also won Big Ten Defensive Player of the Year in 2013. Aranda alongside his OLB coach Tim Tibesar were named Linebacker Coaches of the Year for 2015 by FootballScoop. Over Aranda's three-year span as defensive coordinator at Wisconsin his defense ranked first nationally in total defense, second in scoring defense, third in pass defense and fourth in run defense. His final season with the Badgers his defense came in first in scoring defense, allowing just 13.1 points per game.
On January 1, 2016, it was announced that Aranda was hired to replace Kevin Steele as defensive coordinator for the LSU Tigers. The move to LSU saw his starting salary nearly tripling from $520,000 to starting at $1.3 million. His contract is guaranteed for three years and is not tied to the contract of LSU head coach Les Miles.
Team defensive statistics where Aranda was defensive coordinator.