
In this Y Combinator Startup School talk, Jake Heller, co-founder and CEO of Casetext, explains how his team stopped everything at $20M in revenue to build CoCounsel, the first AI assistant for lawyers, on early access to GPT-4 — a bet that led to a $650 million acquisition by Thomson Reuters. He lays out a practical playbook across three areas: how to pick an idea (target jobs people already pay for, in categories of assist, replace, or do the previously unthinkable), how to actually build reliable AI (map exactly what a professional does, turn each step into prompts or plain code, and grind on evaluations until you pass 97-99% of tests), and how to market and sell it (build a genuinely great product first, price to value, build trust with head-to-head comparisons, and watch out for pilots that never convert to real revenue).
In this episode of Y Combinator's Office Hours, a rotating cast of YC group partners pulls back the curtain on how legendary startups actually began. Using real interview memories of companies like Solugen, CaptivateIQ, Amplitude, Segment, Brex, Jeeves and Nourish, the partners argue that companies such as Airbnb, Stripe and Dropbox looked indistinguishable from every other early-stage startup on day zero. The through-line: greatness comes not from a magical origin but from tens of thousands of decisions, a bias for action, obstinate conviction, clear and honest communication, and the willingness to pivot until you build something people want.
Pando is a San Francisco fintech building a financial ecosystem for high-potential founders. Its flagship product lets ambitious people contractually pool a slice of future earnings above a hurdle (typically 3% above $1M/year) into a shared portfolio, then split the upside evenly. On top of that sits a curated network: Founder Peer Groups of 5-8 vetted operators, an Investor Exchange of 750+ investors, and member events. Founded in 2017 by Charlie Olson and Eric Lax at Stanford GSB, Pando has grown to more than 900 clients in pools projected to earn over $11B.
OneValley is a San Mateo-based global entrepreneurship platform that helps founders launch and scale startups while giving universities, accelerators, enterprises and governments the software to run their own innovation communities. Born from the Silicon Valley accelerator GSVlabs, it rebranded to OneValley in 2020 after its online Passport platform exploded in growth, and today it pairs that software with OneValley Ventures, a $25M seed and pre-seed fund. The mission: take the resources and connections traditionally locked inside Silicon Valley and make them reachable to innovators anywhere in the world.
Mercury is a San Francisco fintech that builds banking and financial software for startups and growth-stage companies. Through partner banks, it offers FDIC-insured checking and savings, corporate cards, treasury, venture debt, bill pay, and an API - aimed at founders who would rather not call a branch manager.
Every is an all-in-one back-office platform for startup founders, bundling free incorporation, business banking, corporate cards, treasury, payroll, HR, benefits, bookkeeping, and taxes into a single dashboard. Founded in 2021 by Rajeev Behera and Barry Peterson and headquartered in San Francisco, the company raised a $22.5M Series A led by Redpoint Ventures in September 2024 to keep replacing the patchwork of tools that consume founders' time.
Leandra Elberger is the Head of Platform at Forum Ventures, New York's leading pre-seed fund and accelerator for B2B SaaS startups. With a career winding through global health, Wall Street, entrepreneurship education, and venture capital, she has built expertise in founder support and community infrastructure. A Tufts grad with an MBA with distinction from Cornell Johnson, she previously served as Studio Director at Cornell Tech and Head of Platform at Atento Capital, and has authored thought pieces on healthcare market opportunities and fintech infrastructure for founders. Her guiding philosophy: a career is a choice that indicates your values.

Vouch is a technology-first insurance broker built specifically for high-growth startups and venture-backed companies. Founded in 2018 by Sam Hodges and Travis Hedge, Vouch has reimagined business insurance with a digital-first platform that lets founders get covered in minutes - not weeks. With over $203M raised, 6,000+ companies insured, and a landmark 2025 deal with Hiscox, Vouch sits at the intersection of fintech and insurtech, offering everything from general liability to first-of-its-kind AI-specific coverage.