Y Combinator hosted its Summer 2025 Demo Day last week, showcasing the latest batch of over 160 startups.

As with recent batches, the majority of startups presented AI-centric solutions. However, a clear evolution was evident. Instead of “AI-powered” products, many companies are now building AI agents or the infrastructure and tools needed to develop them. For instance, this batch had a flurry of voice AI solutions and new businesses focused on helping others monetize the “AI economy” with ads and marketing tools.

We spoke with a handful of YC-focused investors to learn which startups they found most interesting and which generated the highest investment demand.

Below are the most frequently mentioned ones:

Autumn

What it does: Stripe for AI startups

Why it’s a fave: Many AI star

See Full Page