Bruno was born in Concordia, Entre Ríos, and made his international debut at the 2008 South American Youth Championships in Athletics, where he came fourth in the 1500 metres. An appearance at the 2009 World Youth Championships in Athletics followed, but he failed to make it past the first round. He entered the 3000 metres for Argentina at the 2010 Summer Youth Olympics and placed fifth in the "B" final. That same year he ran a series of personal bests: 3:47.35 minutes for the 1500 m (a national junior record), 8:23.51 minutes for the 3000 m and 14:38.70 minutes for the 5000 metres.