President-elect Joseph R. Biden Jr., facing the rise of domestic terrorism and a crippling cyberattack from Russia, is elevating two White House posts that all but disappeared in the Trump administration: a homeland security adviser to manage matters as varied as extremism, pandemics and natural disasters, and the first deputy national security adviser for cyber and emerging technology.

The White House homeland security adviser will be Elizabeth Sherwood-Randall, according to transition officials. She is a longtime aide to Mr. Biden who served under President Barack Obama as senior director for Europe and then deputy secretary of energy, where she oversaw the modernization of the nuclear arsenal.

And for the complex task of bolstering cyberoffense and defense, Mr. Biden has carved out a role for Anne Neuberger, a rising official at the National Security Agency. She ran the Russia Small Group, which mounted a pre-emptive strike on the Kremlin’s cyberactors during the 2018 midterm elections, part of an effort to counter Moscow after its interference in the 2016 presidential election.

For the past 15 months, she has overseen the agency’s Cybersecurity Directorate, a newly formed organization to prevent digital threats to sensitive government and military industry networks. But it has also been an incubator for emerging technologies, including the development of impenetrable cryptography — the National Security Agency’s original mission nearly 70 years ago — with a new generation of quantum computers.

Taken together, the two appointments show how Mr. Biden appears determined to rebuild a national security apparatus that critics of the Trump administration say withered for the past four years. The new White House team will focus on threats that were battering the United States even before the coronavirus pandemic reordered the nation’s challenges.

Transition officials say that Ms. Sherwood-Randall and Ms. Neuberger will be given new powers to convene officials from around the government to deal with emerging threats. Both are expected to begin their jobs on Jan. 20, since neither position requires Senate confirmation.

Ms. Sherwood-Randall will have to oversee the effort to contain right-wing groups that laid siege to the Capitol last week, and Ms. Neuberger will face the aftermath of the most unnerving cyberbreach to affect the federal government. She will, senior officials say, have to help determine how to make good on Mr. Biden’s vow that the hackers behind the recent intrusion, which has spread across government networks, “will pay a price.”

Ms. Sherwood-Randall, a Rhodes Scholar who in recent years has been a professor at the Georgia Institute of Technology, had been considered a candidate for secretary of energy. The job went to Jennifer Granholm, a former governor of Michigan.

She will serve as the White House homeland security adviser, a position created by President George W. Bush that became more powerful under Mr. Obama, and is distinct from the secretary of the Department of Homeland Security, who sits in the cabinet.

“We’re going to be dealing at once again with border security, biosecurity, global public health and strengthening the resilience of our own democracy,” she said in a brief interview. “The last of those have grown more urgent.”

Mr. Trump dismantled the National Security Council’s pandemic preparedness office, and while he had an active cyberteam at the beginning of his term, it languished. “It’s disturbing to be in a transition moment when there really aren’t counterparts for that transition to be handed off,’’ Ms. Sherwood-Randall said.

Ashton B. Carter, the former secretary of defense, who hired Ms. Sherwood-Randall during the Clinton administration, said the “challenge will be rebooting this office.”

He noted that after the collapse of the Soviet Union, Ms. Sherwood-Randall worked to establish relationships with former Soviet republics while “also dismantling their nuclear legacies.”

Mr. Biden also announced that Ms. Sherwood-Randall’s deputy would be Russ Travers, a 42-year veteran of the intelligence community, where he focused on counterterrorism. The Trump administration abruptly replaced Mr. Travers as acting director of the National Counterterrorism Center in March during planned cutbacks by the acting director of national intelligence, Richard Grenell.

Mr. Travers twice postponed retirement to lead the National Counterterrorism Center on an interim basis. But he was so alarmed by what he viewed as the Trump administration’s backsliding on counterterrorism priorities that he shared his concerns with the intelligence community’s inspector general last year in his final weeks on the job.

Over the summer, he predicted a rise in right-wing violence if Mr. Trump was re-elected.

Ms. Neuberger is the grandchild of Holocaust survivors, and her family came to Brooklyn after the failed Hungarian revolution in the 1950s. She began her career in the private sector, directing technology at the American Stock Transfer and Trust Company, until she became a White House fellow, a program that brings talented outsiders into government for a year. But she soon joined the National Security Agency, where she was the first chief risk officer and led the election security effort.

She works closely with Gen. Paul M. Nakasone, the director of the agency and commander of United States Cyber Command. That could ease what has, over the years, been a tense relationship between one of the nation’s largest intelligence agencies and the White House.

But she arrives at a particularly fraught time. The SolarWinds hacking, named after the maker of network management software that Russian intelligence agents are suspected of having breached to gain access to the email systems of government agencies and private companies, was a huge intelligence failure.

Ms. Neuberger acknowledged that it exposed a series of vulnerabilities that the Russian hackers exploited.

“The fact that no intelligence entities or private entities really have an-end-to end picture” of how the attackers operate is a significant problem, she said, “particularly when you have sophisticated adversaries who take steps to hide their activities.”

“There are some very specific ideas and suggestions we’ve learned from working through SolarWinds with some really strong private sector partners,” she said. But she declined to say how Mr. Biden would make good on his vow to punish the hackers.

Eric Schmitt contributed reporting.