As pressure continued to mount when suspected Chinese hackers infiltrated the database of the U.S. Office of Personnel Management, the head of that agency has decided to step down, ending her time in office that last about a year and a half.

Katherine Archuleta, who formerly served as the national political director for the 2012 re-election campaign of President Barack Obama, oversaw an unprecedented data breach of private information that her agency was responsible for protecting, according to the Arkansas Democrat-Gazette.

Authorities believe the hackers working for the Chinese government infiltrated databases and background-check records for millions of people who have applied for U.S. security clearances.

Archuleta at first adamantly refused to step down, saying that she was “committed” to doing her job, but lawmakers — including Democrats — were insistent on her resignation and the pressure only continued to mount. As a result, on Friday morning she submitted her resignation to Obama.

Beth Cobert, the deputy director for management at the Office of Management and Budget, will step in to the role as acting directory of OPM.

Authorities believe that 4.2 million people had their records stolen in the first hack earlier this year, and that 21.5 million had their Social Security numbers and other sensitive information stolen in a second hack that has been called the largest in the history of the United States.

Lawmakers said that the resignation was too little too late, and some argue that the move was not enough to stop the bleeding. The agency still lacks a solid system to protect private data, and since OPM is the largest human resources department in the world, it desperately needs one.

Even more worryingly, lawmakers say that it may be years before the full security ramifications of this hack are fully known, and that it will force the intelligence community to take some large steps to address new vulnerabilities that come with the release of all this data.