Matija was born in Serbia and grew up in New York City. He learned how to swim at the age of four with the Roosevelt Island Marlins, and went on to compete for the Marlins throughout his formative years. Matija was involved in competitive swimming throughout middle school and high school -- qualifying for the Junior Olympics championships several years in a row. He first became an instructor in 2017 -- with the Marlins, at the same pool where he learned to swim. His focus while teaching is to foster a safe environment while having lots of fun. Matija's hobbies include biking all over the city and being involved in various artistic projects.