FullStack Developer - On Site in San Francisco

Principal / Senior Full-Stack Engineer (AI Agents) San FranciscoLocation: San Francisco, CA (4th & King) 100% on-site, 5 days/week Employment Type: Full-time Salary Range: Principal Engineer: $225k$275k + meaningful equity Senior/Staff Engineer: Flexible depending on autonomy and experience About the CompanyWe are a fast-growing, 10-person startup based in San Francisco, building next-generation AI agents powered by the latest models from OpenAI and Anthropic. Since January 2023, the team has been designing, testing, breaking, and refining agent architecturesdeveloping rare and deeply practical expertise in the space. We offer a highly collaborative environment with significant ownership, rapid iteration, and the opportunity to shape core parts of the product. The OpportunityWe are hiring 510 Full-Stack Engineers over the next 12 months to accelerate the development and scalability of our AI Agent platform. We're looking for highly autonomous engineers with deep technical experience who thrive in ambiguous, fast-paced environments. ResponsibilitiesDesign, develop, and maintain full-stack features using TypeScript. Build and optimize AI agents using state-of-the-art LLMs. Work with GCP (primary) or AWS, infrastructure-as-code, and deployment pipelines. Take full ownership of projectsfrom ideation and architecture to implementation and maintenance. Develop reusable tools, prompts, and frameworks for rapid agent creation. Proactively identify problems, propose solutions, and execute independently. Contribute to architectural decisions and engineering best practices. Ideal Candidate ProfileExperience10+ years of engineering experience, used as a proxy for deep ownershipnot just tenure. Strong experience in B2B SaaS environments. Full-stack background with a focus on TypeScript. Cloud experience with GCP (preferred) or AWS. Prior AI agent experience is a plus but not required. Technical SkillsFull-stack TypeScript (frontend + backend). Strong system design and architectural skills. Experience with IaC, CI/CD, deployment workflows. Familiarity with LLMs and genuine enthusiasm for AI innovation. MindsetExtreme ownership: Takes responsibility for outcomes end-to-end. High agency: Proactively finds and solves the right problems. Comfort with ambiguity: Thrives where specs evolve quickly and iteration is constant. Not a good fit: Engineers who need rigid scope, structure, or step-by-step direction. Compensation & BenefitsCompetitive salary: Principal: $225k$275k Senior/Staff: flexible based on autonomy and performance Meaningful equity, benchmarked against Pave and Color. Health, dental, and vision insurance (basic plan fully covered). Commuter benefits (parking & train). Catered meals and office snacks. High-impact role within a small, senior team. Interview ProcessHiring Manager Screen (remote) Coding Challenge (remote) Onsite in SF: 45 min: System Design 45 min: Past Projects Deep Dive 45 min: Founder Conversation / Collaboration Offer stage after references