Y Combinator Startup Podcast

Philip Johnston is the co-founder and CEO of Starcloud, the company building data centers in space.

In November 2025, Starcloud launched an Nvidia H100 GPU into orbit and trained the first large language model in space. They've since raised $200 million, hit a billion-dollar valuation just 17 months after YC demo day, and filed with the FCC to deploy 88,000 more satellites.

In this episode, Philip walks us through their wild origin story, the engineering challenges behind the Starcloud-1, why they booked a SpaceX launch before they even knew what they were building, and how data centers in space make sense both economically and politically.

Waymo’s first autonomous demo took eighteen months. The product took fifteen years. Today, the Waymo Driver runs 500,000 trips a week — four million fully autonomous miles across fifteen cities, with 17 times fewer serious-injury crashes than human drivers.

At Startup School 2026, Waymo co-CEO Dmitri Dolgov shares the seven lessons behind that journey, from bridging the gap between a demo and a real product to building systems that can safely operate in the physical world.

Transcript: https://www.ycrootaccess.com/p/dmitri-dolgov-seven-lessons-from

In 2009, Patrick and John Collison went to Startup School in Berkeley, got sushi in Potrero Hill afterward, and decided on the walk home to start Stripe. The reasoning, as Patrick remembers it, was that “we might as well because it probably won't be that hard.”
It took two years to launch.
Seventeen years later, at Startup School 2026, he talks with YC's Harj Taggar about dropping out of MIT twice, why founders should ask what happens if they succeed, and what Stripe's own data says about the best time to start a company.

In 2001, Jeff Dean and Sanjay Ghemawat did the math and realized Google’s entire search index would fit in RAM — then shipped it in a few days, and search got fast. In 2013, another napkin calculation showed that three minutes of daily speech recognition per user would require doubling Google’s server fleet. That one became the TPU.

At Startup School 2026, Google’s Chief Scientist talks with YC’s Diana Hu through the thought experiments behind both, why inference hardware is the next specialization, and where two or three people in a room can still win.

Transcript: https://www.ycrootaccess.com/p/jeff-dean-the-1-rule-for-building

Alexandr Wang's advice to his 18-year-old self: develop your own internal compass for how the future will unfold, and hold conviction in it against the noise. At Startup School 2026, the Scale AI (YC S16) founder — now leading Meta's Superintelligence Labs — talks with Garry Tan about rebuilding a frontier lab from scratch, why talent density compounds, and how to spot the exponential worth betting your twenties on.