Summary: Harvey, a San Francisco-based legal AI startup, has rapidly grown from a simple idea sparked by a first-year associate using GPT-3 to an $8 billion company serving 700 clients worldwide. Co-founder and CEO Winston Weinberg shares the journey of building Harvey, from cold-emailing OpenAI to tackling complex legal data challenges, expanding globally, and reshaping how lawyers work with AI. With a focus on collaboration between law firms and corporate legal teams, Harvey is pioneering a “multiplayer” platform that respects ethical boundaries and data privacy, all while aiming to enhance legal training and productivity.
From First-Year Associate to AI Startup Founder
Winston Weinberg began his legal career as a first-year associate at O’Melveny & Myers. His journey into legal AI started unexpectedly when his roommate, Gabe Pereyra, who was working at Meta, introduced him to GPT-3. Initially, Winston used GPT-3 for fun, like running Dungeons and Dragons games, but soon realized its potential for legal work during a landlord-tenant case he was assigned.
The Breakthrough Moment with GPT-3
Winston and Gabe developed an extensive chain-of-thought prompt based on California landlord-tenant laws. They tested it on 100 real questions from Reddit’s r/legaladvice and presented the AI-generated answers to experienced attorneys without revealing their source. Impressively, on 86 out of 100 cases, at least two out of three attorneys would have sent the AI’s answer as-is. This validation convinced them that AI could transform the legal industry.
Raising Capital and Navigating Silicon Valley
In July, they cold-emailed Sam Altman and Jason Kwon at OpenAI, pitching their idea. OpenAI’s Startup Fund became their first institutional investor, introducing them to angel investors like Sarah Guo and Elad Gil. Despite having no prior connections in tech or venture capital, Winston focused on building a strong business, believing that success attracts the right investors. Today, Harvey’s cap table includes top-tier firms like Sequoia Capital, Kleiner Perkins, Google Ventures, Coatue, and Andreessen Horowitz.
Scaling Harvey: Clients, Revenue, and Global Expansion
Harvey has grown to serve 700 clients across 63 countries, including most of the top 10 U.S. law firms. The company surpassed $100 million in annual recurring revenue by August 2025 and employs around 400 people. Operating globally presents challenges, especially with strict data residency laws in countries like Germany and Australia, requiring Harvey to maintain compute infrastructure locally to comply with regulations.
The Challenge of Building a Multiplayer Legal AI Platform
One of Harvey’s unique focuses is creating a “multiplayer” platform that enables collaboration between law firms and their corporate clients while respecting ethical walls and data permissions. For example, a law firm working with multiple venture capital firms must ensure sensitive information doesn’t cross boundaries. Harvey is developing robust security and permissioning systems to handle these complexities, with a scalable version expected by December.
How Lawyers Use Harvey Today
Lawyers primarily use Harvey for drafting documents, conducting research (enhanced by a partnership with LexisNexis), and analyzing large volumes of documents during due diligence or discovery. While transactional work like M&A and fund formation remains popular, litigation use cases are growing rapidly as more data becomes available.
Addressing Criticism and Building a Moat
Some critics view Harvey as merely a ChatGPT wrapper, but Winston emphasizes that their strength lies in collecting detailed workflow data and building evaluation frameworks to assess legal document quality. Additionally, their multiplayer platform connecting legal service providers and consumers sets them apart from competitors focused on only one side.
Business Model and Future Growth
Currently, Harvey primarily sells seat-based subscriptions but is transitioning toward outcome-based pricing for specific workflows where AI can guarantee accuracy and speed. The company envisions a hybrid model where AI handles initial passes on tasks like diligence, with lawyers overseeing final reviews.
The Future of Legal Work and Junior Lawyers
Winston is passionate about how AI can enhance legal training. By automating routine tasks, AI tools like Harvey can serve as personalized tutors for junior lawyers, accelerating their path to partnership and improving education through real-time feedback and simulated exercises.
Looking Ahead: Fundraising and IPO Plans
Despite rapid growth and a soaring valuation from $3 billion to $8 billion within a year, Harvey does not plan to raise large funding rounds soon, focusing instead on sustainable growth and preparing for future compute-intensive research. The company is interested in exploring public markets eventually, though no timeline has been set.