Kemboi was born on 10 February 1992.[1] His first international circuit win was at the 2011 Weltklasse in Biberach, where he ran a personal best (PB) of 8:34.22 in the 3000 m steeplechase.[1] He went on to record top-three finishes at several minor meetings over the next few years, including being a pacemaker for steeplechase and 5000 m races.[1][2]
In 2015, Kemboi achieved his first international medal with a win at the African games men's steeplechase, which earned him comparisons to compatriot and Olympic gold medalist Ezekiel Kemboi.[3] He was ranked 8th globally in the men's steeplechase that year by Track & Field News.[4]