Castillo enters his third season as the Assistant Men's Soccer Coach at Florida College. He is also the Head Women's Soccer Coach at FC, and the Assistant Coach for the Tampa Marauders. As a player of Guatemalan descent David Castillo trained with CSD Municipal and Universidad De San Carlos academy team U16-U19. Castillo also played for Rural Youth Soccer Association in Wimauma, FL who were nationally ranked #1 in the nation on gotsoccer.com during his U19 Senior season in 2010. In 2011, Castillo helped lead Florida College to their first USCAA National tournament appearance as a player. In 2012, he was awarded Best Attacking MVP and in 2014 was awarded the captains award, coaches award, and was a USCAA All-American. In 2015, as a first year assistant, Castillo helped guide the program to their second USCAA National tournament and their second final four finish. Castillo played one season for Greater Tampa Bay in the semi-professional Champions Soccer League in 2015.