← More live internships

Summer 2026 Full-Stack Engineer Intern

Thirdlayer

San Francisco, CA, USInternshipPosted September 12, 2026

Full-Stack Engineer Intern We're looking for engineers who can turn research prototypes into production-ready systems. You'll work at the intersection of browser automation, agent infrastructure, and intuitive UX that make complex agent behavior understandable and controllable. Preferred: History of high-achieving projects/work experience, open source contributions, or competitive math/cs/physics experience. What You'll Do • Full-stack browser extension interfaces based on research prototypes. • End-to-end features using React/Next.js, Python, and SQL. • Design intuitive interfaces for how users should delegate and override AI actions. …

See the full posting and apply

The rest of the description, the direct apply link, your match score, a tailored resume and the recruiters to message all come with internOS Pro. 3 days free, then $10/month. Cancel anytime.