
Y Combinator
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Y Combinator
@ycombinator
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Fun update: I got tired of disliking every email client I’ve ever used and built my own. It’s called Exo (for exoskeleton). It’s Claude Code for my inbox. It manages my inbox for me, and it’s open source. Link to repo + some notable features in thread!



We sat down with @PhilipJohnston, co-founder and CEO of @Starcloud_, at MIT to discuss why the future of data centers might be in space. After graduating @ycombinator less than 2 years ago, Starcloud just raised an impressive $170M Series A at a $1.1B valuation led by @benchmark and @eqtventures. The conversation covers everything from solar physics and cooling systems to GPU economics, radiation hardening, launch costs, and satellite design. Philip also shares what it takes to build a unicorn deeptech startup. We discuss his experience with YC, the skepticism around their demoday launch, and the crazy last minute race to get Starcloud’s first satellite onboard their scheduled Falcon flight. Full episode is here on X and at any of the links below (see comment). Timestamps: 00:00 - Intro 01:12 - What is Starcloud? 02:44 - Why do data centers need to go to space? 06:15 - Can’t we just build more solar panels on earth? 11:10 - Economic analysis of Starcloud 19:56 - How does Starcloud’s cooling work? 28:26 - Training an LLM in space 32:07 - Addressing critics on space Twitter 34:23 - Is Starcloud overfunded? 35:59 - Will demand for data centers keep going up? 38:11 - GPU lifespan and disposal in space 39:47 - Bus structures 41:43 - Starcloud’s origin and founders 49:29 - Fundraising, Competition, and Meeting Expectations 53:29 - Satellite size and collisions 56:29 - Manufacturing Bottlenecks 1:00:20 - Starcloud 1 tests 1:01:57 - Acceleration after YC 1:03:43 - Testing on Earth 1:05:06 - Motivations for Starcloud 1:06:45 - Data centers on the Moon 1:08:12 - Interacting with AI companies 1:08:18 - What’s next for Starcloud? 1:14:01 - Other uses for Starcloud satellites 1:17:56 - Lunar hotels and space elevators 1:24:28 - Complementary business ideas to Starcloud 1:29:51 - Philip’s competitive twin 1:32:18 - Philip and Mike’s thoughts on YC 1:36:04 - Advice for young entrepreneurs @elonmusk @DJSnM @Sci_Phile @hankgreen








In this episode of Founder Firesides, YC Managing Partner Jared Friedman talks to Karine Mellata (@karine_exe), co-founder of Variance (@trustvariance), who is coming out of stealth and announcing their $21 million Series A. Variance builds purpose-built AI agents for risk and compliance — automating fraud detection, content review, and identity verification for Fortune 500 companies and platforms like GoFundMe. They discuss why Variance built in the shadows for three years, detecting state-sponsored fraud rings, and the accident that nearly ended the company. 00:49 – The AI That Keeps the Internet Safe 01:28 – Why They Stayed Secret for 3 Years 02:26 – You’ve Used This Without Knowing It 02:57 – How GoFundMe Stops Scams 03:59 – How Scammers Use Big News Events 05:50 – Checking IDs and Businesses Online 07:44 – How the AI Agents Work 09:28 – The Hardest Problem: Bad Data 12:07 – Why This Only Works Now 14:22 – Catching Organized Fraud Groups 16:26 – Tiny Team, Huge Output 20:18 – How They Met at Apple 22:24 – Getting Their First Customer 24:57 – Recovering from Getting Hit by a Truck 29:36 – Sticking to One Big Idea


















