Whilst studying for his law degree at the University of New South Wales, Miller worked in a commercial law firm in
Sydney. After graduating from the University of New South Wales, in 1999 Miller joined DFAT full-time. Returning to Australia, Miller then served as a desk officer in DFAT's South-East Asia Division from 2003–2006, and then as Director of DFAT Corporate Planning from 2007–2009. In 2009, Miller was then moved to the position of Director in DFAT's Afghanistan Section. With this appointment, Miller became the first
Indigenous Australian to become an Australian head of mission. Miller took up his appointment in May 2013 and presented his credentials to
Queen Margrethe II on 14 June 2013. He later presented his credentials to
Norwegian King Harald V on 17 October 2013 and to
Icelandic President Ólafur Ragnar Grímsson on 7 December 2013. On his Ambassadorial appointment, Miller noted that the Department employs 49 Indigenous staff with 12 of those employees posted at various
Australian diplomatic missions around the world, and that it is "great honour not only for me, but for my family and for Indigenous Australians." == Personal life ==