Poolside

Poolside is building AI models specifically designed for software engineering — not general-purpose LLMs adapted for code, but models trained from the ground up to understand, write, and reason about software. The company argues that code-specific models will outperform general models at programming tasks because they can be optimized for the unique structure and logic of software.

Founded by Jason Warner (former CTO of GitHub) and Eiso Kant, Poolside has raised $500M at a $3B valuation despite being pre-product — a bet on the team's ability to build the best code-specific AI. The company's approach involves training on vast repositories of code, execution traces, and debugging sessions, not just raw code text.

Poolside represents the 'vertical model' thesis — that domain-specific models trained deeply in one area will surpass general-purpose models for specialized tasks.