Poolside

Poolside is an American artificial intelligence company headquartered in San Francisco, founded in May 2023 by Jason Warner (former Chief Technology Officer at GitHub and Heroku) and Eiso Kant (former founder of source-code-analysis startup source{d}). The company develops foundation models specifically optimized for software engineering, with commercial enterprise focus and a distinctive bet on "Reinforcement Learning from Code Execution Feedback" (RLCEF) for software-engineering capability. As of April 2026, Poolside is one of the principal commercial coding-foundation-model labs, with $500 million Series B in October 2024 at approximately $3 billion valuation, Department of Defense partnership commitments, and continued enterprise customer expansion.

At a glance

• Founded: May 2023 in San Francisco by Jason Warner and Eiso Kant.
• Status: Private. Series B in October 2024 at approximately $3 billion valuation.
• Funding: Approximately $626 million-plus cumulative private capital. Series B of $500 million in October 2024 at approximately $3 billion valuation, led by Bain Capital Ventures with DST Global, Citi, Nvidia, and other investor participation.
• CEO: Jason Warner, Co-Founder and Chief Executive Officer. Former Chief Technology Officer at GitHub (2017 to 2021) and Heroku.
• Other notable leadership: Eiso Kant, Co-Founder and Chief Technology Officer. Former founder of source{d}.
• Open weights: Limited. Poolside develops commercial foundation models for software engineering rather than open-weights releases.
• Flagship products: Poolside foundation models specifically optimized for software engineering through RLCEF; commercial enterprise deployments; Department of Defense partnership.

Origins

Poolside was founded in May 2023 by Jason Warner and Eiso Kant. Warner had been Chief Technology Officer at GitHub from 2017 to 2021, anchoring senior leadership credibility on developer-tooling and software-engineering applications. Kant had been the founder of source{d} (a source-code-analysis startup, founded 2015 and subsequently wound down in 2021), with prior experience on code-analysis-foundation-model research.

The 2023 to 2024 emergence of large-language-model-powered code-generation capability had anchored commercial interest in coding-foundation-model applications, with Poolside's founding thesis explicitly oriented around foundation models specifically optimized for software engineering through RLCEF.

The October 2023 $126 million Series A funding round at approximately $475 million valuation, led by Felicis Ventures, anchored early commercial-development resources. The October 2024 Series B of $500 million at approximately $3 billion valuation, led by Bain Capital Ventures with DST Global, Citi, Nvidia, and other investor participation, was the company's most consequential commercial transition.

The 2024 to 2026 period has continued commercial enterprise customer expansion and Department of Defense partnership commitments.

Mission and strategy

Poolside's stated mission is to build artificial general intelligence through software engineering. The strategic premise reflects 2023 to 2026 commercial interest in coding-foundation-model applications, with Poolside explicitly positioning itself as a frontier coding-foundation-model lab with the RLCEF approach providing a distinctive technical bet.

The strategy combines three threads. First, the Poolside foundation models specifically optimized for software engineering. Second, the RLCEF technical approach providing distinctive software-engineering capability. Third, commercial enterprise deployment and Department of Defense partnership.

The competitive premise reflects Poolside's distinct positioning as a frontier coding-foundation-model lab with enterprise-customer focus, distinguishing it from peer commercial coding-AI products from frontier AI labs and peer autonomous-coding-agent labs.

Distribution channels include direct enterprise commercial deployment and Department of Defense partnership.

Models and products

• Poolside foundation models. Specifically optimized for software engineering through RLCEF. Enterprise commercial deployment.
• Reinforcement Learning from Code Execution Feedback (RLCEF). Technical approach for software-engineering capability.
• Department of Defense partnership. Continued commercial commitments through 2024 to 2026.

Distribution channels include direct enterprise commercial deployment and Department of Defense partnership.

Benchmarks and standing

Poolside's evaluation framework focuses on software-engineering capability metrics rather than horizontal foundation-model leaderboards. Industry coverage has consistently characterized Poolside as one of the principal commercial coding-foundation-model labs globally, alongside Cognition AI, Cursor (Anysphere), Codeium / Windsurf, and other peers.

The RLCEF technical approach has been characterized as a distinctive technical bet for software-engineering foundation models.

Leadership

As of April 2026, Poolside's senior leadership includes:

• Jason Warner, Co-Founder and Chief Executive Officer.
• Eiso Kant, Co-Founder and Chief Technology Officer.
• Senior engineering and product leadership.

Continued senior engineering recruitment has supported commercial enterprise customer expansion.

Funding and backers

• Series B (October 2024): $500 million at approximately $3 billion valuation, led by Bain Capital Ventures with DST Global, Citi, Nvidia, and other investor participation.
• Series A (October 2023): $126 million at approximately $475 million valuation, led by Felicis Ventures.
• Earlier capital: Seed and earlier-stage capital.

Industry position

Poolside occupies a distinctive position as one of the principal commercial coding-foundation-model labs globally, with Series B backing at approximately $3 billion valuation, Department of Defense partnership commitments, and commercial enterprise customer expansion.

Competitive landscape

• Cognition AI. Direct autonomous-coding-agent peer.
• Cursor (Anysphere), Codeium / Windsurf, Magic. Coding-AI peers.
• Anthropic Claude Code, OpenAI Codex, Google DeepMind Jules. Frontier AI lab coding-AI alternatives.
• BigCode Project. Open-research code-foundation-model peer.
• GitHub Copilot (Microsoft). Enterprise coding-AI peer.

Outlook

• The continued Poolside foundation model development and RLCEF research output through 2026 to 2027.
• Continued commercial enterprise customer expansion.
• The continued Department of Defense partnership trajectory.
• Continued senior engineering recruitment.
• The Series C or adjacent fundraising timeline through 2026 to 2027.

Sources

• Poolside official site. Company reference.
• Poolside Series B announcement. October 2024 funding announcement.
• Bain Capital Ventures. Lead Series B investor.
• Jason Warner LinkedIn. Co-Founder reference.
• Poolside on TechCrunch. Industry coverage.