John Colombi began his coaching career at Castle Rock Recreation Center in 2007. After three years in this position, he contributed as an assistant coach with the Parker Hawks and Mustangs football programs. Between 2011 and 2017, John Colombi shifted his focus to coaching lacrosse, though his time with the Cougars and Raptors lacrosse programs overlapped with his work as a football coach.

He was particularly impactful with the Cougars, elevating the team from the least-competitive Blue level to the competitive Red level. More recently, John Colombi has served the Warriors lacrosse program as an assistant coach and the Rock Canyon High School program as head of the junior varsity team.

In addition to his work as an athletics coach, John Colombi has a decade of experience as a firefighter with the New York City Fire Department (FDNY). Over the course of his time as a member of the FDNY, he demonstrated the ability to remain calm and make quick decisions in highly pressurized situations. As a firefighter, he received the Fire Bell Club Medal of Honor in recognition of bravery and meritorious service during a fire, as well as the Firefighters Quarterly Bravest Award.