Bain & Company is using generative AI to rapidly build functional replicas of target companies’ products, a practice called "vibecoding," to test technology defensibility during private equity due diligence. The practice, detailed in recent Financial Times reporting, has already produced hundreds of rough prototypes and is contributing to a sharp slowdown in deal activity. Rebecca Burack, head of Bain’s global private equity practice, explained the value: “It’s kind of the difference between seeing something in 2D versus 3D… We are leveraging vibecoding to show what a software company can and can’t do.” If Bain’s team can recreate the core user experience in days using publicly available AI tools, it raises questions about a seller’s real moat, as modern software products are often built on familiar tech stacks and commoditized infrastructure. The timing of Bain’s expanded use of vibecoding coincides with a dramatic pullback in technology, media, and telecom (TMT) private equity deal activity.