In The Arena
How Anastasios Angelopoulos and Wei-Lin Chiang Built AI's Most Trusted AI Evaluation Platform
Matt Quinn
Arena Infrastructure, AI
00:00
Felicis led Arena's Series A, after previously investing in the company's seed round.
Founders
- Anastasios Angelopoulos — CEO and Co-Founder
- Ion Stoica — Co-Founder
- Wei-Lin Chiang — CTO and Co-Founder
Headquarters
San Francisco, California
Website
Stage
Seed
Domains
- Infrastructure
- AI
Status
Current
About Arena
Arena is the industry-standard, human-driven benchmark platform for evaluating AI models, turning millions of real-world user votes into the leaderboards that model labs and enterprises rely on to understand true model performance. Users submit a prompt, two anonymous model responses appear, and users vote for the stronger answer. Founded in 2025 by Anastasios Angelopoulos, Wei-Lin Chiang, and Ion Stoic the company grew out of a UC Berkeley research project (Chatbot Arena) into a platform used by over 5 million people across 150 countries each month, with labs like OpenAI, Google, and Anthropic relying on it for real-world evaluation data.
Perspectives
