Robert Nishihara
About Robert Nishihara
Robert Nishihara is a co-founder of Anyscale, the company behind Ray, an open-source AI compute engine. Ray is used to scale machine learning training, inference and data processing. Laude's profile lists him as Anyscale's co-founder and CEO.
He studied math at Harvard and earned a PhD in machine learning and distributed systems at UC Berkeley. During the PhD he worked in the RISELab with Michael Jordan. Tracxn dates his start-up career to 2019 with Anyscale, and Crunchbase lists him in Los Altos, California.
Press coverage describes Anyscale as a managed platform for developing and deploying AI applications on Ray. A Frontlines podcast episode says the company has raised over $250M.
Public records of his angel activity are thin. Crunchbase shows 2 personal investments, and Tracxn shows 1. Tracxn lists a Letta investment dated September 23, 2024, with the round type unattributed. Crunchbase lists RadixArk's seed round as his latest investment. Check sizes and ownership stakes are not public.
RadixArk raised a $100M seed round, which the Lounge deals desk dates to January 2026. A May 2026 angel registry newsletter describes RadixArk as AI infrastructure for training and deploying frontier AI models. It names Accel, Spark Capital, NVentures and AMD among the investors, plus many angels, and lists Nishihara as one of those angels.
Letta, from 2024, is the other AI-related investment on record.
Tracxn lists his top investment sectors as High Tech and Enterprise Applications, with portfolio companies in the United States. His two known investments, RadixArk and Letta, are both AI companies, and his operating background is in AI infrastructure. He has made no public statement about the stages he prefers, his check size or what he looks for in founders. The RadixArk investment was an angel check in a $100M seed round that institutional investors led, so he has invested alongside large funds.
- RadixArk: AI infrastructure for training and deploying frontier AI models; $100M seed round, January 2026, with Nishihara participating as an angel.
- Letta: Tracxn records an investment on September 23, 2024; the round type is not specified.
- oreilly.com/people/robert-nishihara
- laude.org/impact/robert-nishihara
- crunchbase.com/person/robert-nishihara
- tracxn.com/d/people/robert-nishihara/__zY3KB2y2nOCu_xyUnYs_N3shkPas1hL
- buttondown.com/AngelRegistry/archive/angel-registry-update-may-6-2026
- x.com/robertnishihara
- frontlines.io/podcasts/robert-nishihara
- fastcompany.com/91244222/how-anyscale-cofounder-robert-nishihara-is-fi
Investing activity
Robert Nishihara appears in 1 AI deal tracked by the Lounge deals desk, rounds totalling $100M. The rounds are mostly Seed, with a median round size of $100M. The most recent is RadixArk (Seed, $100M, Jan 2026).
Robert Nishihara most often invests alongside Spark Capital, Accel, AMD and Hock Tan, and the companies they back on Lounge are mostly in AI Infrastructure.
Deals
Frequently asked questions about Robert Nishihara
Does Robert Nishihara invest as an angel?
Yes. Crunchbase and Tracxn both list him as an individual or angel investor, with 2 and 1 recorded investments respectively. These include RadixArk's seed round and Letta.
What does Robert Nishihara do besides investing?
He is a co-founder of Anyscale, the company behind the open-source Ray framework, and is listed as its CEO. He also co-created Ray.
What is Robert Nishihara's check size?
No check size is public. Founders should not assume a figure.
What sectors does Robert Nishihara back?
Tracxn lists High Tech and Enterprise Applications. His known investments are AI companies, and his own work is in AI infrastructure.
Has Robert Nishihara invested in AI seed rounds?
Yes. He took part in RadixArk's $100M seed round, which the Lounge deals desk dates to January 2026.
How can founders reach Robert Nishihara?
He is active on X at @robertnishihara, where his profile links to his personal site, robertnishihara.com. A relevant, specific note that draws on his work on AI infrastructure and Ray is the sensible way to start.
Is Robert Nishihara an angel investor?
Yes. Robert Nishihara invests personally as an angel.
What AI companies has Robert Nishihara invested in?
Robert Nishihara's AI investments include RadixArk. The 1 round on Lounge are listed on this page with amounts, dates and co-investors.
What stage does Robert Nishihara invest at?
In the rounds tracked on Lounge, Robert Nishihara has invested at Seed, with a median round of $100M.
Who does Robert Nishihara co-invest with?
Robert Nishihara's most frequent co-investors on Lounge are Spark Capital (1 deal), Accel (1 deal), AMD (1 deal), Hock Tan (1 deal) and John Schulman (1 deal).