Y Combinator S25 Batch Showcases Surge in Technical AI Founders and Infrastructure Focus

SAN FRANCISCO, CA – The latest Y Combinator (YC) Summer 2025 (S25) batch, culminating in its Demo Day presentations in September, is distinguished by a significant increase in technically proficient founders and a pervasive focus on artificial intelligence (AI) across various applications. Tomer London, Co-founder and Chief Product Officer at Gusto, shared his observations after meeting the batch, highlighting key trends that set this cohort apart.

London noted a marked shift towards deeper technical expertise among the founders. "Founders are more technical than ever. I absolutely love that," he stated, indicating a strong foundation in engineering and computer science within the new wave of startups. This technical depth is seen as a crucial enabler for the complex AI solutions being developed.

A dominant theme within the S25 batch is the overwhelming prevalence of AI-focused companies. Unlike previous cycles, the current AI ventures are characterized by clearer, more practical use cases. "Obviously most companies are AI focused, but the use cases are much clearer and rooted in real customer pain," London explained. This suggests a maturation in the application of AI, moving beyond theoretical concepts to address tangible market needs.

Furthermore, the batch demonstrates a growing emphasis on AI infrastructure, particularly in areas akin to "Scale AI for X." London observed that these foundational AI infrastructure companies are "gaining real traction now that there's a significant business ecosystem around AI." This trend points to a robust and expanding AI industry that requires specialized tools and platforms to support its growth.

Gusto, a comprehensive platform for payroll, benefits, and HR, continues to be a favored choice among YC companies. London expressed gratitude, stating, "Thank you YC companies for choosing Gusto consistently to help start up and run your business. We're your biggest fans here at @GustoHQ." This ongoing partnership underscores Gusto's role in supporting the operational needs of emerging tech ventures.

Overall, London conveyed strong optimism about the S25 cohort. "Overall, very impressed. It's going to be a fantastic batch," he concluded, anticipating significant innovations and developments from these startups as they prepare for their public debut at Demo Day.