Kiboro joined Esso Kenya Ltd. in 1974 as a Supply, Planning and Economics Manager, where he started gaining both managerial and executive recognition.
In 1999, the NMG made their entry into the electronic media industry after many years of frustration due to policy inadequacies and hostility by the then Government of Kenya under Daniel arap Moi.
It is divided into: The NMG has also taken advantage of the communications technology explosion to send news to their subscribers, in partnership with Safaricom and Airtel, leading mobile operators in Kenya.
Kiboro has travelled extensively, holding numerous national, regional and international job assignments that have seen him supervise cross-national teams across continents, a vote of confidence in his abilities as a change manager.
He also sits on The Rhodes Trust in Kenya as Honorary chairman and is a member of the International Organisation of Employers' Enterprise Advisory Group.