Building foundation models specifically for software development
HQ: San Francisco, CA, United States | Founded: 2023 | Employees: ~150 | Stage: Late Stage VC | Website: https://poolside.ai
Poolside AI is an American artificial intelligence company that trains its own foundation models specifically for software development and sells them to enterprises and regulated-industry customers who run the system on-premises or inside their own clouds. Founded in May 2023 by Jason Warner, the former CTO of GitHub, and Eiso Kant, a serial developer-tooling entrepreneur behind source{d} and Athenian, the company's core technical bet is Reinforcement Learning from Code Execution Feedback (RLCEF) — a training methodology that generates synthetic data from code execution rather than relying on proprietary customer code.
The company's flagship products include the Malibu and Point first-generation models, and from April 2026, the Laguna model family — including Laguna S 2.1, a 118-billion-parameter mixture-of-experts model with 1 million token context that is both open-weight and available via API. Poolside targets large enterprises with 5,000+ developers, particularly in highly regulated industries like financial services, defense, and government. Notable customers include RTX Corporation (served via AWS Bedrock) and the U.S. Department of Defense.
In August 2026, Poolside struck a landmark deal with Nvidia: a $6 billion non-exclusive license to its Model Factory platform, a $1 billion equity investment at $12 billion pre-money valuation, and Nvidia making offers to hire 109 Poolside engineers. The deal is explicitly not an acquisition — Poolside's founders retain control and the company continues operating independently.
Poolside AI is a frontier AI lab that trains its own foundation models for software engineering, differentiating through on-premises deployment for regulated enterprises and a proprietary Reinforcement Learning from Code Execution Feedback (RLCEF) training approach. The company's August 2026 landmark deal with Nvidia — a $6B non-exclusive Model Factory license, $1B equity investment at $12B pre-money valuation, and offers to 109 employees — represents one of AI's most unusual transactions, effectively validating Poolside's model-development platform while preserving its independence.
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