Y Combinator+

New Operating Systems for the Physical World

Most of the global workforce does not sit at a desk, but the software used to manage physical work has barely changed in decades. The next operating systems will coordinate humans, robots, and AI agents together. The companies that build them could manage far more than software workflows. They could manage the labor itself. So if you're building this new kind of operating system for the physical world, we'd love to hear from you. Apply for the Fall 2026 batch at ycombinator.com/apply.

How Two French Engineers In New York Built The Company That Monitors The Entire Cloud

In this chat at Startup School Paris, Datadog CEO Olivier Pomel reflects on his startup journey in New York, how staying close to raw customer feedback and support tickets keeps an 8,000 person company honest, and why moving faster on both hiring and firing remains the hardest thing for any founder to actually execute. Apply to Y Combinator: https://www.ycombinator.com/apply Work at a startup: https://www.ycombinator.com/jobs Chapters: 00:00 — Intro 01:43 — How Datadog Actually Started 04:47 — The DevOps Insight Behind the Company 06:17 — Riding the Cloud Explosion 07:29 — Was It Ever Obvi

Opencode CEO: Blocked, 20X Growth in 6 Months, Building the Coding Agent for the World

Jay V is the founder and CEO of Opencode, an open-source alternative to Claude Code that works with any model you want. It's one of the fastest-growing products in AI: 13 million monthly active users, 20X growth this year, and more tokens processed daily than all of OpenRouter. But the overnight success took 16 years, one legal entity, and nine YC applications. In this episode of the Lightcone, Jay explains how Anthropic's attempt to block Opencode accidentally fueled its rise, how 16 years of near-misses prepared him to catch lightning in a bottle, and why most of the world still hasn't exp

How Photoroom Trained Themselves To Dream Bigger

In this chat from Startup School Paris, the founders of Photoroom expand on why going through YC transformed their ambition from a vague dream of building a billion-dollar company into a concrete, achievable plan. Apply to Y Combinator: https://www.ycombinator.com/apply Work at a startup: https://www.ycombinator.com/jobs Chapters: 00:00 — Intro 00:27 — What Is Photoroom? 01:21 — Did You Know It Could Be This Big? 01:59 — How YC Changed Their Ambition 03:24 — Learning to Say "Billion" Out Loud 04:52 — Demo Day: Fastest Growing in the Batch 06:53 — Why Europeans Fear Big Ideas 08:12 — Why Am

The Best Time to Build in Crypto

Crypto is in a bear market, but the underlying technology is becoming more useful than ever. Stablecoins are spreading across financial institutions, tokenized assets are reshaping trading, fintech companies are quietly building on crypto rails, and AI agents may rely on them to transact. The hype may be down, but the opportunity to build is not. Apply for the Fall 2026 batch at ycombinator.com/apply.

AI for the Aging Population

By 2030, one in five Americans will be over 65, and there are nowhere near enough caregivers to support them. AI could help older adults live safely and independently through better voice interfaces, monitoring, robotics, and tools for family caregivers. It is one of the world’s largest and most underserved markets, and it is growing every day. If you're building for the aging population, we'd love to hear from you. Apply for the Fall 2026 batch at ycombinator.com/apply.

Scientists Are Built for Startups

If you’re a scientist or researcher, you may be more prepared to start a company than you think. Before becoming founders, Arvind Veluvali, Ayman Saleh, and Dima Yanovsky all worked at NASA, where they learned to tackle hard problems, run experiments, and keep going when the outcome was uncertain. You don’t need a business background. You just need the ambition to build. If you're making something people want, we'd love to hear from you. Apply to the Fall 2026 batch by July 27th: ycombinator.com/apply

The Model-Agnostic AI Platform Betting That No Single Lab Will Win

In this discussion at Startup School Paris, Dust co-founder Stanislas Polu reflects on his path from Stripe to OpenAI and why he and his co-founder decided to build their company in France. Apply to Y Combinator: https://www.ycombinator.com/apply Work at a startup: https://www.ycombinator.com/jobs Chapters: 00:00 — Intro 01:09 — From Stripe to OpenAI to Founder 02:49 — Why Stan Left OpenAI 03:46 — What Dust Actually Does 04:07 — What Work Looks Like in 3 Years 05:10 — Where the Thesis Was Right (and Wrong) 07:05 — The Horizontal vs. Vertical Debate 09:15 — Model Agnostic as a Moat 10:49 —

AI-Powered Consumer Products for 1 Billion People

Every major platform shift creates new consumer giants. But three years into the AI era, ChatGPT is still the only new icon on most people’s home screens. As intelligence gets better and dramatically cheaper, nearly every consumer category opens up again: education, health, finance, entertainment, transportation, and how we connect with each other. Consumer is going to be so back. If you’re building for a billion people, we’d love to hear from you. Apply for the Fall 2026 batch at ycombinator.com/apply.

How Supabase Became One Of The Fastest Growing DevTool Companies In The World

In this conversation from Startup School Paris, Supabase CEO Paul Copplestone explains how a frustrating firebase migration led to an open-source side project that became one of the fastest-growing dev tool companies in the world. Apply to Y Combinator: https://www.ycombinator.com/apply Work at a startup: https://www.ycombinator.com/jobs Chapters: 00:00 — Intro 00:56 — Paul's Origin Story 02:13 — Two Failed Startups First 04:12 — Why Postgres? Why Open Source? 07:11 — The Pivot That Actually Worked 08:03 — Targeting YC Startups from Day One 09:45 — Fully Open Source — The Risky Choice 12:0

Compute at Sea

AI is running out of compute, and data centers are running out of electricity and land. One possible solution is to move compute offshore. The ocean offers abundant space, sunlight, and natural cooling, opening the door to fleets of modular data centers operating together as a global cloud. We want to fund founders who are bringing the world’s compute to the oceans. Apply for the Fall 2026 batch at ycombinator.com/apply.

Multiplayer AI

The best work tools became more powerful when they became multiplayer. But AI is still mostly trapped in private chats, with agents working in sessions that teammates can’t join or influence. The next generation of AI tools will let teams work with agents together in real time: watching, redirecting, and handing off work across engineering, sales, support, legal, finance, and more. AI’s multiplayer moment is coming. So if you’re building AI that’s multiplayer by default, we’d love to hear from you. Apply for the Fall 2026 batch at ycombinator.com/apply.

A Cloud for Small Software

Agents make it easy to build personal tools for yourself or your team. But deploying, securing, and sharing that software is still far more complicated than creating it. A cloud built for small software could remove that complexity and make bespoke tools as easy to share with a colleague as a Google Doc. If you’re working on something like this, we’d love to hear from you. Apply for the Fall 2026 batch at ycombinator.com/apply.

The Future of American Defense

Warfare is at an inflection point, and the old ways of Army acquisition simply don't keep pace with modern threats. The Army is replacing the old playbook with commercially developed, modular technology that can be deployed and improved quickly. We're looking for founders building low-cost interceptors, next-generation sensors, drones, resilient logistics, advanced manufacturing, and hardware that can survive the world’s harshest environments. There has never been a better time to build for the Army. Apply for the Fall 2026 batch at ycombinator.com/apply.

The Primer

The best education has always come from one-on-one tutoring, but that privilege has historically been reserved for very few people. AI could give every child a patient, adaptive tutor that grows with them over the years, beginning with reading, writing, and arithmetic, and eventually helping them learn to think and reason. For the first time, Neal Stephenson’s Primer is starting to feel possible. If you're building this, we'd love to hear from you. Apply for the Fall 2026 batch at ycombinator.com/apply.

Why Ambitious Startup Ideas Are Actually Easier To Sell

In this discussion from Startup School Paris, PostHog CEO James Hawkins reflects on a number of startup topics including going from one product to twenty, why European founders need to stop focusing on negative possibilities, and the benefits of swapping jobs with your co-founder. Apply to Y Combinator: https://www.ycombinator.com/apply Work at a startup: https://www.ycombinator.com/jobs Chapters: 00:00 — Intro 00:53 — From Analytics to Self-Driving Software 02:00 — The Recursive AI Loop 03:25 — Why Products Need Intent Data 05:43 — Pull Requests Before Humans Arrive 07:05 — The Thousand T

World Models, JEPA And The Path To Sample-Efficient RL

In this episode of Decoded, Ankit and Francois walk through the motivation and math behind world models. They cover a number of areas including why sample efficiency is one of the biggest unsolved problems in AI, how deterministic differentiable control and Newtonian physics represent a "perfect world model," and why the action space explosion makes chess tractable but robotics nearly intractable. Apply to Y Combinator: https://www.ycombinator.com/apply Work at a startup: https://www.ycombinator.com/jobs Transcript: https://ycrootaccess.substack.com/p/world-models-an-intuitive-introduction

YC's Head of Design Shows You How To Design With AI

AI isn't just changing the tools designers use. It's changing the way they think, prototype, and build. In this episode of Design Review, YC Head of Design Eve Bouffard joins General Partner Aaron Epstein to share the AI-first workflow she uses to design products, websites, and events. Using projects like Paxel, SOTA Zine, and YC Startup School as examples, she explains how coding agents are transforming everything from rapid prototyping and branding to design systems, and why the biggest bottleneck is no longer software. It's imagination. Paxel: https://paxel.ycombinator.com SOTA Zine: htt

Dot Plots: How to Actually See What Your Users Are Doing

One of the biggest mistakes founders make is relying on aggregate user metrics instead of understanding how any individuals use their product. In this episode of Startup School, YC General Partner David Lieb walks through one of his favorite tools for better understanding your users, the dot plot. It’s a simple two-dimensional grid that maps individual user activity over time and it can help separate signal from the noise in the early days of a startup. He’ll cover why it gives founders a better sense of product health compared to aggregate metrics, what patterns to look for and real-world exa

Solving the Blank Canvas Problem: Gusto's AI Co-Founder

Eddie Kim is the co-founder and Head of Technology at Gusto (W12), a payroll and HR platform serving over 500,000 small businesses in the U.S. that recently crossed $1 billion in annual revenue — with one in five new businesses started today becoming Gusto customers. Recently, Eddie built Gusto Cofounder, a new AI product that automates recurring business processes end-to-end, all triggered through SMS or Slack without the business owner ever logging in. In this episode of Founder Firesides, Eddie sat down with YC Managing Partner Harj Taggar to explain how he built the first working prototy

India Can Create The Largest AI Companies

In this final panel from Startup School India, the hosts reflect on why India's deep technical talent makes it uniquely positioned to produce some of the world's largest companies in this new AI wave and how young founders can break out of conventional advice from traditional education systems to reach their full potential. Apply to Y Combinator: https://www.ycombinator.com/apply Work at a startup: https://www.ycombinator.com/jobs Chapters: 00:00 —Intro 02:56 — $100M ARR with one engineer 03:47 — Why AI is different from mobile 05:25 — No US network? No problem 07:38 — YC founders are gett

Zynga Founder: Consumer Is Not Investible Right Now - Thats Why You Should Build It

Mark Pincus is the founder of Zynga and author of "Life at the Speed of Play: Launch Products People Love", which distills the product philosophy and founder playbook he developed across five companies. In this episode of the Main Function, Pincus sits down with Garry to talk about consumer in the AI age and why the opportunity has never been greater. https://www.lifeatthespeedofplay.com/ Apply to Y Combinator: https://www.ycombinator.com/apply Work at a startup: https://www.ycombinator.com/jobs 00:00 — Intro 01:09 — Why Mark wrote the book 03:44 — Three eras of the Internet 04:22 — How

How to Get Your First 10 Customers

When most founders look for customers, they reach for cold email and automation tools. But your first 10 customers almost never come from a tool. They come from you, working your warm network and doing the unscalable things most people won't. In this episode of Startup School, YC Visiting Partner Max Kolysh breaks down the real tactics for getting those first 10 customers — where your buyer actually spends their time, why showing up in person wins, and why doing it yourself is your biggest advantage right now. Apply to Y Combinator: https://www.ycombinator.com/apply Work at a startup: https:

The Age Of The 40-Year-Old Solo Founder Is Here

Bryant Chou co-founded Webflow, which today powers around 1% of all websites on the internet. Now he's back in the current YC batch with Ploy, an AI-powered website and marketing platform that doesn't just build your site — it connects to your analytics, CRM, and search console to optimize your marketing while you sleep. In this episode of the Lightcone he explains how he built Ploy to be “anti slop,” how building today compares to his first startup, and why founders with domain expertise are making a comeback. Chapters: 00:00 — What Experience Gives You in the Age of AI 00:38 — Meet Bryant C

Pick One Idea and Go Deep

Many founders get stuck trying to find the perfect startup idea before they commit. But the perfect idea doesn't exist in the abstract. The only way to find what works is to pick one, go deep, and get feedback from real customers. In this episode of Startup School, YC General Partner Jon Xu breaks down how to choose what to build, "burn the other boats," and go deep enough to practically run your customer's business— and why that depth is what surfaces the better idea underneath. Apply to Y Combinator: https://www.ycombinator.com/apply Work at a startup: https://www.ycombinator.com/jobs Cha

Groww: If Your Customers Don't Love It or Hate It, You've Already Lost

Lalit Keshre is the co-founder and CEO of Groww (W18), India's largest retail investment platform, offering stocks, mutual funds, and wealth management products to millions of customers. At Startup School India, Keshre sat down with YC General Partner Jon Xu to reflect on what it takes to build fintech products at the highest level. Chapters: 00:00 - Intro 01:32 - Growing Up Wanting to Be an IAS Officer 03:41 - The First Idea That Failed 05:36 - The Counterintuitive Bet on Transparency 07:30 - 600 Customers in the First Month 09:20 - WhatsApp Groups & Movie Theater Interviews 11:09 - 100%

Self-Play for LLMs, AI for Biology, Formal Verification, and More | YC Paper Club

It's hard to keep up with the latest AI research. That's why we started YC Paper Club — a small group of researchers, engineers, and founders who meet every two weeks at our Mountain View office to present and discuss new papers together. In this session, we cover whether scaling laws hold for protein biology, AlphaZero-style self-play for language models, streaming RAG for real-time voice agents, formal verification with Lean, and why one founder thinks programming with agents is exactly like playing a real-time strategy game. Stay tuned for more. Interested in joining a future Paper Club? A

How Meesho Became India’s Biggest Shopping App

Vidit Aatrey is the co-founder and CEO of Meesho (S16), an e-commerce platform built for mass-market India that has grown to about 1 millions sellers and 2.5 billion annual orders. Since launching in July 2021, It has become the largest shopping app on Android in India. In this fireside chat at Startup School India, Vidit sat down with YC General Partner Ankit Gupta to go over how he and his co-founder went from studying small business WhatsApp groups in Bangalore to building a full out social commerce platform. https://meesho.com Apply to Y Combinator: https://www.ycombinator.com/apply Wor

The Most AI-Pilled CEO We Know

Brex co-founder and CEO Pedro Franceschi believes most people still underestimate how much AI will change the way companies are built. AI isn't just another tool, it's a new foundation for building products, teams, and companies. In this episode of Lightcone, Pedro shares why he thinks we're only months into a platform shift as significant as the invention of electricity, how AI has changed the way he works, and why every founder should be "token maxing" to understand the limits of the technology firsthand. He explains why the CEO needs to be the chief AI officer, how Brex is rebuilding itse

Startup School is back!

Two days, packed with world-class speakers, hands-on demos, small group sessions with YC partners, and a room full of the most ambitious technical builders from around the world. July 25–26 in San Francisco. http://ycombinator.com/startupschool

Emergent: How Six Months of Tinkering Led To A $100M ARR Company

Mukund Jha is the co-founder and CEO of Emergent, a platform that lets anyone without programming knowledge build, ship, and monetize real software by chatting with an AI agent. Launched roughly nine months ago, Emergent has surpassed 8.5 million users across 190 countries, seen more than 10 million apps built on the platform. At Startup School India, Mukund sat down with YC Managing Partner Jared Friedman to go over his founder journey and insights from building two successful companies. https://emergent.sh Apply to Y Combinator: https://www.ycombinator.com/apply Work at a startup: https