From 1987, Jandosov worked as a junior researcher at the Institute of Economics of the Academy of Sciences of the Kazakh SSR.
Jandosov became its chairman in January 1996 and, while serving in that position, was a member of the Supreme Economic Council under the President of Kazakhstan from February until November 1997.
However, a few days later, Jandosov announced that he could not take this position because the head of Air Kazakhstan Erkin Kaliev being his relative.
[5] On 20 June 2003, he was appointed as the chairman of the Agency of the Republic of Kazakhstan on Regulation of Natural Monopolies and Protection of Competition as part of the Council for Economic Policy.
On 29 April 2005, the Nagyz Ak Zhol (literally True Bright Path) party was formed, headed by four co-chairs which were Jandosov himself, Bulat Abilov, Tulegen Zhukeyev and Altynbek Sarsenbayuly.
[8] In September 2005, Jandosov became the deputy head of the campaign headquarters for support of Zharmakhan Tuyakbay in the 2005 Kazakh presidential election.