Kristie Canegallo, center, is seen in the Oval Office on April 1, 2014, as President Obama gets an update about the Affordable Care Act. (Pete Souza/The White House)

President Obama on Friday appointed longtime White House aide Kristie Canegallo as deputy chief of staff for policy implementation, to oversee issues that include the continuing rollout of the Affordable Care Act and better integration of technology in classrooms.

The move, which comes three days before senior White House health-care adviser Phil Schiliro will step down, aims to institutionalize some of the changes chief of staff Denis McDonough made in the wake of the health-care law’s botched debut last fall.

In an interview, McDonough said Canegallo, 34, will ensure the president is following through on some of the major policies set in motion during his first term. Her portfolio will include reforming how the federal government procures technology, veteran’s affairs and immigration policy, as well as national security topics such as data privacy and the withdrawal of troops from Afghanistan.

“The president, when we go through a formative experience or a big event, he wants us to make sure we capture the lessons learned — in this case, health care — so we do not make the same mistakes,” McDonough said. “He has directed that we maintain senior-level focus on implementation and execution in the White House.”

Unlike many of Obama’s top advisers, who came to their jobs through politics, Canegallo started as a civilian Pentagon official on detail to the White House when Obama came into office in 2009. Trained as a credit derivatives analyst at Goldman Sachs, she served as director in the National Security Council’s Defense Policy and Strategy Directorate for two years before becoming senior adviser to McDonough, who was then the president’s deputy national security adviser.

Thomas E. Donilon, who served as national security adviser during Obama’s first term, said in an interview that Canegallo has a “tremendous breadth of experience” and rose through the ranks because of her political management skills.

“She ran the deputies meetings at the NSC, which is really the principal management tool that NSC uses for implementing policy,” he said.

Jim Miller, a former undersecretary of defense who worked with Canegallo at the Pentagon, said she possesses “a rare combination of strategic thinking and being detail-oriented.”

Canegallo worked at the U.S. Embassy in Afghanistan in 2007 and served in Iraq in 2008 as a governance and budget adviser to the Anbar provincial government. Miller said the stints gave her “a granular view of how to get things done on the ground.”

Canegallo is comfortable with the long hours required of senior White House officials; Donilon recalled that Canegallo’s mother “would come by the staff office pretty frequently” to visit her.

Canegallo helped salvage the federal online health insurance marketplace after it experienced massive technical problems when it went live on Oct. 1.

Chris Jennings, who served as a senior White House health-care adviser during the rollout, said Canegallo “monitored every piece of data that came in” in the weeks following the launch of and helped her colleagues sort it out when they were “drowning in conflicting information” about the system’s performance.

On April 1, when the White House released a photo of a small group of staffers informing the president that enrollment under the law had surpassed 7 million, White House communications director Jennifer Palmieri tweeted, “That’s Kristie Canegallo, Denis’ secret ACA weapon, briefing ­POTUS on numbers. Right 4 her to be in center of pic.”

McDonough said Canegallo will coordinate preparation for the next enrollment period, upcoming policy announcements related to the law and “making sure insurers understand the rules of the road” as the system moves forward.

Miller said that while Canegallo will face difficult terrain in her new post, he is confident she understands both the possibilities and the limitations.

“You can’t serve in Iraq and Afghanistan without being, or becoming, a realist,” he said. “She’s a realist and has an understanding of what it takes to get stuff done.”