Allen & Overy (now A&O Shearman) + Harvey
2023-2024
Allen & Overy was one of the first global firms to roll out Harvey — a GPT-4-based legal AI platform — to thousands of lawyers across 40+ offices. The deployment followed a months-long pilot with hundreds of lawyers testing real-world use cases (contract analysis, due diligence, drafting). The firm paired the rollout with mandatory training and a clear acceptable-use policy that kept AI-generated output inside a verification workflow before it reached clients.
Lesson
The legal AI winners are not the firms with the best model — they are the firms that paired the model with a real verification workflow, training program, and acceptable-use policy. Skip those layers and you ship a hallucination engine into a profession that gets sanctioned for hallucinations.