AP
McDonough, 43, has been with the President for some of his largest accomplishments, as an adviser to the President's 2008 campaign and later as his most trusted national security aide (a position that earned him a seat in the room where the White House monitored the Navy SEAL raid that killed Osama bin Laden.)
According to The Atlantic's Caren Bohan, McDonough is "well-liked" among the White House staff and is known to express personal gratitude to hardworking staffers. Former White House Deputy Communications Director Jen Psaki describes him as "the hardest worker on the planet."
Earlier this month, the Washington Post's David Nakamura profiled McDonough's role in the White House over the past several years, describing him as an intense worker active around the clock who could be sharp-tongued and dismissive as well:
McDonough, described as among the hardest-working and most demanding of Obama’s top aides, also can come across as sharp-tongued and dismissive. He is known to carry White House note cards in his pockets, whipping them out to scribble messages during meetings, which he passes around the room. Most of the notes are questions about policy but some can be mocking insults, said one official who has attended the meetings. He also is not adverse to cursing those who have frustrated or angered him, associates said.
McDonough's primary expertise is national security. He started his White House career as the senior strategist on communications for the National Security Council. Two years ago he was promoted to deputy national security advisor under National Security Advisor Tom Donilon.
He is a devout Catholic and advised the president on an approach to take with the contraception mandate in the Affordable Care Act.
McDonough will not need to go before the Senate for a confirmation hearing, as the Chief of Staff is not a Cabinet position and therefore does not need Congressional approval.