Castro served as an assistant to Chot Reyes from 2002 with Coca-Cola Tigers,[2] San Miguel Beermen, and Talk 'N Text Tropang Texters.

[3] Castro also served as an assistant coach for Philippine Team from 2005 to 2007.

[4] Castro became manager of Tropang Texters from 2010[4] until 2013, when Paolo Trillo take over.

[3][6] Before coaching, Castro served as a senior manager for Procter & Gamble.

[3] After coaching, he founded CleanTech Global Renewables, and served as its CEO.