Ion Stoica

Stoica earned an M.S. in computer science and control engineering from the Polytechnic University of Bucharest in 1989 and a Ph.D. in electrical and computer engineering from Carnegie Mellon UniversityCarnegie Mellon UniversityCarnegie Mellon University (CMU) is a private research university in Pittsburgh, Pennsylvania. It grew out of the Carnegie Technical Schools, founded with funding from Andrew Carnegie in 1900, which were renamed the Carnegie Institute of Technology in 1912 and took the present name after merging with the Mellon Institute in 1967. The university is known for computer science, robotics, engineering, and the arts, and has campuses in Qatar, Silicon Valley, and Rwanda. As of September 2025, it enrolled 16,582 students. Its current president is Farnam Jahanian. On September 30, 2026, the university announced a $3 billion gift from Ken Griffin and plans to build a new campus in Miami.Open the full entry in 2000, and received the ACMAustralian Community MediaAustralian Community Media (ACM) is an Australian regional and rural news publishing group with more than 100 brands, including The Canberra Times; in 2019 Nine sold it to a company controlled by interests associated with Antony Catalano and Thorney Investment Group.Open the full entry Doctoral Dissertation Award in 2001.⁠[1]

In 2006 Stoica co-founded Conviva Networks.⁠[2]

In 2012 Stoica was named an ACM Fellow for contributions to “networking, distributed systems, and cloud computing.”⁠[1][3]

In 2013 Stoica co-founded Databricks.⁠[2]

In 2019 Stoica co-founded Anyscale. That year he received the ACM SIGOPS Mark Weiser Award.⁠[2][1]

Stoica became an honorary member of the Romanian Academy in 2022, received the IEEE Koji Kobayashi Computers and Communications Award in 2023, was elected to the National Academy of Engineering in 2024, and received Berkeley’s Fiat Lux Faculty Award in 2025. He earlier received the ACM SIGOPS Hall of Fame Award in 2015 and the ACM SIGCOMM Test of Time Paper Award in 2011.⁠[1]

LMArena, which runs Chatbot Arena, grew out of a UC Berkeley research project and launched as a standalone company in April 2025. On the platform, users submit prompts, compare anonymous model responses and pick the better one. On May 21, 2025, LMArena announced a $100 million seed round led by Andreessen HorowitzAndreessen HorowitzAndreessen Horowitz (a16z) is a venture capital firm founded in 2009 by Marc Andreessen and Ben Horowitz. It invests from the seed stage through the growth stage and provides operational support to its portfolio companies.Open the full entry and UC Investments, with Lightspeed Venture PartnersLightspeed Venture PartnersLightspeed Venture Partners backs companies from seed through late-stage financing. Its website distinguishes Lightspeed Management Company (LSVP) from Lightspeed India Partners (LSIP): the two are separately operated investment advisers, with the U.S., European, and Israeli offices belonging to LSVP and the India and Southeast Asia offices belonging to LSIP.Open the full entry, Felicis VenturesFelicisFelicis (whose funds and earlier brand use the name Felicis Ventures) is a venture capital firm based in Menlo Park, California, founded in 2006 by former Google product manager Aydin Senkut; it has invested in companies including Shopify, Canva and Adyen.Open the full entry and Kleiner Perkins participating, at a $600 million valuation; Stoica is co-founder and executive chairman.⁠[4]

In April 2025 a paper by researchers from Cohere, Stanford, MIT and Ai2 accused LMArena of helping some AI companies improve their leaderboard scores; Stoica said the study contained “inaccuracies” and “questionable analysis.” He also said, “We believe evaluations are more important now than when we started.”⁠[4]

On May 29, 2025, Andreessen Horowitz released the AI + a16z podcast episode “Beyond Leaderboards: LMArena’s Mission to Make AI Reliable,” hosted by a16z’s Anjney MidhaAnjney MidhaAnjney Midha is an entrepreneur, investor, and researcher, the founder of AMP, and a visiting scientist in applied physics at Stanford University. He co-founded Ubiquity6, led developer platform ecosystem work after the company was acquired by Discord, joined Andreessen Horowitz in 2023 to work on AI investing, and currently serves at the firm as a Venture Partner.Open the full entry, in which Stoica, as LMArena co-founder and chairman, appeared with co-founder and CEO Anastasios N. Angelopoulos and co-founder and CTO Wei-Lin Chiang; the video was uploaded to the a16z YouTubeYouTubeYouTube is Google’s video-sharing and creator platform, founded in 2005 by Steve Chen, Chad Hurley, and Jawed Karim and acquired by Google in 2006. Built around video uploading, viewing, and creator earnings, the platform has developed Shorts, YouTube Music, Premium, YouTube TV, and products for children, and is headquartered in San Bruno, California, United States.Open the full entry channel the same day.⁠[5][6]

The discussion covered why static benchmarks struggle to keep pace with real-world deployment, testing models through large numbers of user votes, how Arena grew from a research side project into a significant part of the AI stack, resisting overfitting and gaming, the move from academic project to company, personalized leaderboards and evaluation SDKs, and open source and agents.⁠[5]

Stoica is a professor of computer science at the University of California, Berkeley, where he holds the Tony XuTony XuTony Xu is the co-founder and chief executive officer of DoorDash and a member of the Meta board of directors. He holds a bachelor’s degree in industrial engineering and operations research from the University of California, Berkeley, and an MBA from Stanford University; his career spans management consulting, internet products, and local commerce services, and he has also made early-stage investments in companies.Open the full entry and Patti Bao Chancellor’s Chair and directs the Sky Computing Lab; his research lies at the intersection of AI and systems, cloud computing and distributed systems. Early in his career he received a Presidential Early Career Award for Scientists and Engineers (PECASE) in 2002 and a Sloan Research Fellowship in 2003.⁠[1][2]

Open-source projects he has worked on include Apache Spark, Ray, vLLM and SkyPilot.⁠[2]

Personal website: https://people.eecs.berkeley.edu/~istoica/ (opens in a new window).⁠[2]