Summer 2026 Full-Stack Engineer Intern

Dex (Y Combinator W25) is seeking Full-Stack Engineer Interns for Summer 2026 to transform research prototypes into production systems, working across browser automation, agent infrastructure, and user-facing design in San Francisco. Key responsibilities include converting prototypes into full-stack browser extension interfaces, developing end-to-end features using React/Next.js, Python, and SQL, designing interfaces for delegating and overriding AI actions, and integrating iMessage, communications channels, desktop-native, and wearables platforms. Required: Strong React/Next.js and TypeScript foundation, experience shipping complex web apps or browser extensions, Figma design systems familiarity. Preferred: Meaningful open-source contributions, strong UI/UX design portfolio, background in high-achieving projects, competitive math/CS/physics. Sample projects include tool call components for LLM responses, indexing/search architecture, security guardrails, and third-party platform integrations (Slack, Notion, Gmail). Compensation: $6K-$10K monthly. US citizen or visa holders only.