The so-called Department of Government Efficiency, led by billionaire Elon Musk, has appeared at agency after agency to slash spending and cut the federal work force. Here’s how DOGE employees do it. Many of DOGE’s actions have been blocked or reversed by the courts. Even still, Mr. Musk’s team has fanned out across the government, taking new positions of leadership in agencies and becoming a part of the fabric of the federal bureaucracy it has sought to reshape.