Poolside Review 2026

Foundation-model company building enterprise-grade AI software engineers trained on private code with on-prem deployment.

Poolside is one of the highest-funded AI labs of the current cycle, founded by Eiso Kant (GitHub, source{d}) and Jason Warner (former GitHub CTO), with a roughly half-billion-dollar Series B. The company is laser-focused on a single bet: training and deploying foundation models that act as software engineers inside large enterprises, with the model itself living in the customer's environment. The pitch to CIOs is that Poolside trains a base model and then continues training on the customer's private code, build logs, incident history, and internal documentation, producing an in-house model that knows the company's stack at a depth no public copilot can match. The platform includes the model, IDE integrations (VS Code, JetBrains), an agent runtime that can plan and execute multi-file changes, evals, and observability — all deployable on the customer's GPUs or in a dedicated cloud region. Poolside is sold exclusively through enterprise contracts and is in flight with Fortune 500 banks, defense primes, and telcos. It competes most directly with Anthropic Claude for code, Cognition (Devin), Magic, and Microsoft's GitHub Copilot Enterprise tier, and differentiates on data residency, custom training, and a willingness to ship into air-gapped environments. Profile flagged for manual verification given the enterprise-only go-to-market.