Feinberg appears to be among the less controversial nominations from President-elect Trump.
Among the more controversial picks is former Fox News personality, Pete Hegseth, to lead the Pentagon, despite his history of alleged scandals and sexual assault.
But Feinberg will certainly face scrutiny on Capitol Hill for his lack of experience to oversee the Department of Defense, which oversees some 3 million military and civilian personnel.
The chief job of the deputy secretary is to be in charge of day-to-day business, managing the Pentagon budget and working with the defense industry on programs and innovation.
Feinberg currently serves as co-CEO of the investment firm Cerberus Capital Management, which he co-founded in 1992.
Before founding Cerberus, Feinberg worked with investment banking firms Gruntal & Co. and Drexel Burnham Lambert.
In Trump's first term, Feinberg served as head of the President's Intelligence Advisory Board, which provides the commander-in-chief with independent advice on effectiveness of the intelligence community.
His experience as a financial investor could prove valuable in the management of the Defense Department's budget.
Cerberus has also invested in defense firms working on hypersonic missiles and previously owned a private military contractor called DynCorp.
The Washington Post, which first broke the news of Feinberg's selection, also reported that some critics have questioned whether there is a conflict of interest in his appointment to the No.2 role.
"Having this revolving door of people who sit on boards of major defense contractors and then cycle in and out of the Pentagon is a problem that did not begin with Trump, but is a problem nonetheless," Matt Duss, executive vice president at the progressive Center for International Policy, told the newspaper.
Read more at TheHill.com.
