The two have the task of merging the 42 ministries formed in the Grand Coalition Government between former President Mwai Kibaki and ex-Prime Minister Raila Odinga.
Kenyatta and Ruto have to think of how they will slash down the ministries to have between 14 and 22 ministries as required by the Constitution.
The two leaders will be expected to release a list that reflects equality based on region and gender, which have been pertinent issues in the country.
Complaints have been made in the past that in such appointments those in leadership make use of the opportunities to reward their cronies.
However, Kenyatta has pledged that he will observe inclusiveness in his governance to ensure youth, women and people from all regions are part of his government.
Insiders say losers in the just concluded election are unlikely to make the list of Cabinet secretaries and may have to contend with other government jobs.
Once the list of nominees is ready it will be forwarded to the Speaker of the National Assembly who will notify the House on the list, then forward it to the Committee on Appointments.
The committee will then decide if all the names will be tabled before the House at once or if it will submit nominee after nominee.
Parliament will then discuss the names for approval.
Kenyatta and Ruto will also be required to forward another list of diplomats representing Kenya, principal secretaries and heads of parastatals to Parliament, for similar vetting.
Before the new constitution, the president would make direct appointments of ministers, diplomats and heads of departments without Parliament’s input.
During his speech to the joint sitting of Parliament on Tuesday, the president said his government will be committed to serving Kenyans efficiently by addressing education, health, security and, among others, food security.
He warned that his government will have zero tolerance to corruption.