Before being promoted to cabinet, Rotich served as head of macroeconomics at the
Treasury from 2006. He was credited with crafting key policy frameworks over the following years, the under the leadership of minister
Robinson Njeru Githae. Rotich served as minister of finance during Kenyatta's first term in office. During his first term, he launched the world's first Treasury bond to be offered exclusively via mobile phone and slashed the minimum investment level in government debt, in a bid to stimulate public participation in the capital markets, raise money cheaply and boost the national savings rate. Also under his leadership, Kenya secured a $1.5 billion loan from the
International Monetary Fund (IMF) in 2016, one of the biggest the IMF had granted on the continent up to that point. Under a restructuring deal overseen by Rotich in 2017, the Kenyan government took over 48.9 per cent of
Kenya Airways after it had suffered five years of losses, including a Ksh26.2bn loss in 2015/2016, the biggest in Kenyan corporate history. Rotich was retained in his position after the
2017 elections. For the 2018 fiscal year, he cut the government's spending budget by 55.1 billion shillings ($546.90 million), or 1.8 percent. Shortly after, he unveiled a package of initiatives to develop
Islamic finance in the country, as part of efforts to mobilize local funds and set Nairobi as a regional hub for the sector. He also announced plans to introduce a set of reforms for the financial sector aimed at boosting private sector credit growth after it was hit by a cap on commercial interest rates introduced in 2016. == Corruption allegations, arrest and removal from government==