Daniel H Callahan

At the end of 2018, Callahan retired as global head of operations and technology at Citigroup. At Citigroup, he managed a complex set of businesses and services spanning more than 100 countries, plus critical systems infrastructure including the bank's cybersecurity initiatives. Earlier in his career, he spent 12 years at IBM where he was director of strategy for IBM Japan. He currently is on the board of Tat Consultancy Services LTD.