1From DeepMind to Dungeons & Dragons
Gabriel Pereyra had an unusual path. He earned a Bachelor's in Computer Science from USC, briefly pursued a PhD in Neuroscience at Oxford, then landed at the heart of AI research: Google Brain, DeepMind, and Meta AI.
In 2022, Pereyra was working at Meta when he started playing with GPT-3. His roommate at the time was Winston Weinberg—a first-year associate at the law firm O'Melveny & Myers. Pereyra showed Weinberg the AI, initially to help run a Dungeons & Dragons campaign.
"Winston was using GPT-3 to run D&D games with friends in LA. But then he started testing it on legal work—and we both realized this could change everything about how law gets practiced."
— Gabriel Pereyra
2The Cold Email That Changed Everything
Pereyra and Weinberg saw the opportunity: AI could automate the labor-intensive grunt work that junior lawyers spend their lives doing—document review, contract analysis, legal research. They decided to build it.
But they needed access to the best AI models. So Pereyra did something audacious: he cold-emailed Sam Altman, CEO of OpenAI.
Pereyra's email worked because it was credible: a DeepMind researcher with deep technical expertise, partnered with a practicing lawyer who understood the problem. The combination was compelling.
Altman responded. OpenAI became Harvey's first investor. In November 2022, Harvey launched with $5 million from the OpenAI Startup Fund—along with backing from Jeff Dean (head of Google AI), Elad Gil, and Sarah Guo.
3Building the Legal AI Powerhouse
Harvey didn't build just another chatbot. They created AI specifically trained for legal work—understanding case law, contract language, and the nuances of legal reasoning. The product could do in minutes what took junior associates hours.
Major law firms signed on quickly. Allen & Overy became one of the first elite firms to publicly adopt Harvey. Others followed. By 2023, Harvey had raised $23 million from Sequoia Capital.
4The Perfect Founder Match
What makes Harvey special isn't just the technology—it's the founder combination. Pereyra brings world-class AI expertise from the very labs that invented modern AI. Weinberg brings firsthand knowledge of what lawyers actually need.
Pereyra now serves as President, directing research and the technical roadmap. Weinberg, as CEO, handles strategy and client relationships. The combination of deep tech and deep domain expertise is rare—and powerful.
Gabriel Pereyra (President):
DeepMind, Google Brain, Meta AI. Technical vision.
Winston Weinberg (CEO):
O'Melveny & Myers associate. Domain expertise.
5Key Lessons for Founders
1. Cold emails work when you're credible
Pereyra's email to Altman worked because he had the credentials to back it up. Credibility opens doors that boldness alone can't.
2. Pair tech with domain expertise
A DeepMind scientist alone couldn't build Harvey. A lawyer alone couldn't either. The combination created something neither could build solo.
3. Move fast on platform shifts
Harvey was founded weeks after GPT-3 showed what was possible. First-mover advantage in AI applications is massive.
4. Start with experiments
Harvey started as roommates playing with AI for D&D. The biggest companies often start as playful experiments.
5. Pick regulated industries
Law is complex, regulated, and expensive. These "hard" industries often have the biggest opportunities for AI disruption.