Y Combinator
MurmurCast publishes AI-generated summaries of Y Combinator’s YouTube episodes — 31 summarized so far, covering Committing to a single startup idea, Going deep on customer understanding, Qualities of good AI-era startup ideas, Founder-market fit, Idea validation through customer immersion, Product-market fit and pivot from robo-advisor to transparent marketplace. Each summary distills the key insights, topics, and takeaways so you can decide what’s worth your time before pressing play.
How To Pick A Startup Idea
YC partner John argues that founders should stop overthinking startup ideas and instead commit fully to a single idea, going deep on customer understanding. He presents a rubric for validating ideas through immersive customer research and outlines three qualities of strong AI-era startup ideas. He emphasizes that even failed deep dives produce valuable data and often surface better underlying opportunities.
Groww: If Your Customers Don't Love It or Hate It, You've Already Lost
Lalit Keshre, co-founder of Groww, discusses the company's journey from a failed robo-advisor to India's largest investment platform, emphasizing customer obsession, radical transparency, and organic growth. He shares how Groww achieved product-market fit within 10-15 days of launching their revamped product in May 2017 by showing all investment products with full transparency. The conversation covers co-founder alignment, navigating regulation, and how AI is lowering barriers to building consumer products.
5 Papers That Show Where AI Research Is Heading Right Now
A research meetup covering five AI topics: protein language model scaling laws (ESM Cambrian), self-play for LLMs (SGS algorithm), streaming RAG for voice agents, formal verification with Lean, and agentic software engineering workflows. Presenters demonstrate how foundational AI scaling principles are transferring into biology, mathematics, and production engineering.
How Meesho Became India’s Biggest Shopping App
Vidit Aatrey, co-founder of Meesho, discusses the company's evolution from a local fashion marketplace to India's largest shopping app with 250 million annual buyers. He explains how customer obsession drove multiple pivots, including abandoning their successful WhatsApp-based social commerce model to launch a direct consumer app in 2021. He also shares how AI is now the next frontier for reaching the remaining 750 million potential Indian consumers.
The CEO Must Be the Chief AI Officer
Pedro Franceschi, co-founder and CEO of Brex, discusses how his company has gone deep on AI adoption, from personal use of Claude to enterprise-wide deployment of AI agents. He argues that CEOs must personally lead AI transformation, treating it as a company-wide refounding rather than a departmental initiative. The conversation covers AI agent security, token spend management, customer world models, and the broader philosophical shift required to build companies in an AI-native way.
Startup School is back!
Former attendees of YC Startup School share testimonials about how the event inspired them to found startups and apply to Y Combinator. The event is praised for its high-caliber speakers, community of ambitious peers, and its role as a gateway into the startup ecosystem. Attendees strongly encourage others to attend, calling it one of the most impactful experiences of their lives.
Emergent: How Six Months of Tinkering Led To A $100M ARR Company
Mukun, co-founder of Emergent, discusses how his AI-native no-code platform reached $100M ARR and 8.5 million users in just 9 months after launch. He shares his journey from Google to Dunzo to Emergent, explaining how six months of post-burnout tinkering with AI models led to the founding insight. He also offers advice on thinking globally from day one and betting on exponential AI progress.
We just launched Paxel!
Paxel is a newly launched tool that analyzes Claude and Cursor coding sessions locally to generate a personalized 'builder profile' across five dimensions. It runs in Docker, keeps code private, and is free to use. Y Combinator is also integrating Paxel tokens into their Startup School application process.
Max Junestrand, CEO of Legora
Max Junestrand, CEO of Legora, discusses how he recruited Jude Law for a marketing campaign, his journey through Y Combinator, and Legora's growth from a small startup to nearly $100M+ ARR with ~500 employees. He also addresses competitive strategy against large AI platforms and the shift toward agentic AI workflows in legal tech.
How Conductor CEO Charlie Holtz Sets Up His Team Of AI Agents
Charlie Holtz, co-founder of Conductor, demonstrates his AI-agent orchestration workflow where he manages multiple Claude and Codex agents simultaneously on his Mac to build software without writing code himself. He discusses opinionated design decisions, 'slot-free zones' to prevent AI code quality degradation, and his philosophy that code is becoming 'sawdust' — a byproduct of well-crafted prompts. The interview covers token spending, tech stack, and his vision of humans as conductors of AI orchestras.
How to Build an AI-Native Services Company
This transcript outlines a playbook for building AI-native services companies, where AI does the bulk of work to deliver outcomes in large markets like tax, law, and insurance. The speaker covers market selection, team formation, product building, sales strategy, and P&L structure. The core thesis is that these businesses can achieve software-like margins (50%+) on markets two to three times larger than traditional software.
Why Two IIT Engineers Turned Down $550K Jobs To Build A Startup
Varun, co-founder of GigaML, shares his journey from IIT student to building an AI customer support company, having turned down a $550K quant firm job offer. The company pivoted multiple times before finding product-market fit in AI customer service agents, winning major clients like DoorDash and top crypto exchanges. Varun reflects on lessons around selling before building, the outsized leverage of coding agents, and the value of 'burning the boats' to force real commitment.
Inference, Diffusion, World Models, and More | YC Paper Club
The inaugural YC Paper Club at Pioneer featured five presentations on cutting-edge AI research topics including speculative decoding for faster LLM inference, diffusion model predictive control for robotics, world models, generalization theory, and data-efficient pre-training. The event brought together researchers and founders in the Bay Area to build a community bridging academic research and startup development. Each presenter shared novel algorithms and findings aimed at advancing AI capabilities, efficiency, and theoretical understanding.
How to Build Superintelligence Inside Your Company
YC General Partner Pete Kumman describes how Y Combinator built internal AI agent infrastructure over the past year, including a shared tool registry with 350+ tools, a centralized database for agent context, and self-improving skill loops. The conversation covers the principles behind building 'superintelligence' inside organizations through shared context, transparency, and agentic workflows that compound organizational knowledge over time.
Why Good Companies Go Bad (And How to Stop It)
Eric Ries, author of 'The Lean Startup,' discusses his new book 'Incorruptible,' arguing that shareholder primacy is a recent and destructive legal norm that causes good companies to lose their missions. He presents structural alternatives like Public Benefit Corporations, dual-class shares, and industrial foundation models to help founders protect their companies long-term. Case studies from Costco, Novo Nordisk, and Anthropic illustrate how mission-first governance structures outperform standard Delaware CC Corp practices.
OpenAI: $2M in tokens to every YC company in the spring and summer batches.
OpenAI is offering $2 million in API tokens to every YC company in the spring and summer batches, invested via an uncapped SAFE at the Series A valuation. The deal is aimed at founders who are heavily consuming tokens to build AI-powered products rapidly. Applications must be submitted by May 25th, with decisions communicated by June 5th.
How to Build a Self-Improving Company with AI
The speaker argues that AI enables companies to move beyond traditional hierarchical structures toward self-improving recursive AI loops. Rather than using AI as a productivity tool bolted onto existing workflows, companies should redesign themselves around AI-native systems that learn and improve autonomously. The talk uses YC's own internal AI systems as live examples of this paradigm shift.
Why Zepto's Aadit Palicha Turned Down Stanford to Deliver Groceries
Aadit Palicha, co-founder of Indian quick-commerce grocery startup Zepto, discusses how he turned down Stanford at 17 to build a 10-minute grocery delivery company during COVID-19, starting from a WhatsApp group in Mumbai. He explains how relentless customer focus, a pivot to dark stores, and obsessive supply chain optimization turned a neighborhood delivery experiment into a billion-dollar platform employing over 200,000 people.
Thanks for a great time, India 🇮🇳
A brief celebratory event in India drew an unexpectedly massive turnout, with over 25,000 applications received. Speakers expressed excitement about the energy in the room and optimism about India's AI future being shaped by the current generation of participants.
Paul Graham, Founder of Y Combinator, Live from Stockholm
Paul Graham argues that ambitious founders should move to Silicon Valley, at least temporarily, to access superior talent networks, serendipitous meetings, and a unique pay-it-forward culture. He also contends that Swedish founders returning home after this experience—ideally through Y Combinator—are one of the best mechanisms for building Stockholm into the Silicon Valley of Europe.