Caliandro was born in Francavilla Fontana. In his first appearance on the world stage, he ran in the 1500 metres at the 1999 World Youth Championships in Athletics, but did not progress beyond the heats. He also competed at the European Youth Olympic Festival that year and he won the gold medal in the 800 metres. His first major medal came at the 2001 European Athletics Junior Championships, where he became the 1500 metres champion.