A chief executive at the age of 30
Born in Mitchelstown in 1969, he attended Clongowes Wood and studied law in Trinity College Dublin.
After leaving TCD, Mr O’Callaghan worked in London in the mergers & acquisitions department of Morgan Stanley and then moved on to rival US investment bank Smith Barney before joining Credit Suisse First Boston’s (CSFB) London office in 1997 to head up its telecoms and technology unit.