On an afternoon in mid-May, dozens of Microsoft engineers and their managers gathered online and in a conference room at the company’s Redmond, Washington, headquarters to discuss Project Glasswing. The tech giant was racing to fix weaknesses in its code that a new AI model known as Mythos was uncovering at an unprecedented clip. The AI behemoth Anthropic, which developed Mythos, had given access to select organizations that make software used by regular people, companies, and governments across the world. The version being used by Microsoft, Claude Mythos Preview, was surfacing bugs faster than the tech giant could patch them, and engineers, the manager said, were now in “a mad dash” to close the gap. “Please, please, please if your org has any April bugs, drive those down,” engineering manager Hans Andersen implored the group.