Ms. Nielsen has extensive professional experience in the areas of homeland security policy and strategy, cybersecurity, critical infrastructure, and emergency management. She is the first nominee for this position to have previously worked within the Department of Homeland Security, having served there in two administrations, first as senior legislative policy director for Transportation and Security Administration under President George W. Bush and then as Department of Homeland Security Chief of Staff under President Trump. Before joining the Trump Administration, Ms. Nielsen founded a risk and security management consulting firm. She previously served as Special Assistant to the President and senior director for prevention, preparedness, and response on the White House Homeland Security Council under President George W. Bush, in addition to serving as a corporate attorney and as a congressional staff member.