In February 2025, Andrej Karpathy, former director of AI at Tesla and co-founder of OpenAI, introduced a term that would reshape how millions think about software development. “There's a new kind of coding I call 'vibe coding,'” he wrote on social media, “where you fully give in to the vibes, embrace exponentials, and forget that the code even exists.” By November 2025, Collins Dictionary had named “vibe coding” its Word of the Year, defining it as “using natural-language prompts to have AI assist in writing computer code.”
The concept struck a nerve across industries far beyond Silicon Valley. By March 2025, Y Combinator reported that 25 percent of startup companies in its Winter 2025 batch had codebases that were 95 percent AI-generated. “It's not like we funded a bunch of non-technical founders,” emphasised Jared Friedman, YC's managing partner. “Every one of these people is highly technical, completely capable of building their own products from scratch. A year ago, they would have built their product from scratch, but now 95% of it is built by an AI.”
Y Combinator's CEO Garry Tan confirmed the trend's significance: “What that means for founders is that you don't need a team of 50 or 100 engineers. You don't have to raise as much. The capital goes much longer.” The Winter 2025 batch grew 10 percent per week in aggregate, making it the fastest-growing cohort in YC history.