Nixon was Science Foundation Ireland Research Professor in Distributed Systems at University College Dublin (2005–2010).
He has extensive industry and commercial experience, collaborating with global high tech firms such as Microsoft, Oracle, IBM and Intel.
He was an IBM faculty fellow at the Dublin Institute for Advanced Studies and from 2007 to 2010 he was Academic Director of Intel's Independent Living and Digital Health.
He was also instrumental in the establishment UCD's Complex and Adaptive Systems Laboratory focusing on inter-disciplinary research at the intersection of mathematics, computation, and scientific discovery.
Nixon's sudden departure from the University of Canberra attracted media attention when it was revealed that he received the highest remuneration of any vice-chancellor in Australia.