Senior Fullstack Software Engineer, AI Agents

11x.ai

4h • $150,000 - $250,000 • Onsite

About The Position

At 11x, we're building autonomous digital workers that handle routine work end-to-end, freeing humans to focus on what they do best—creating, innovating, and building meaningful relationships. We're one of the world’s fastest-growing AI companies. We've achieved a 20x increase in ARR and raised $75M+ from leading investors including a16z and Benchmark. Our team works in-person in our San Francisco office. We're looking for a fullstack engineer with a passion for applied research and cross-functional collaboration. In this role, you’ll work closely with engineering leadership and our AI partners to prototype, build, and scale the next generation of autonomous digital workers. This is an immersive opportunity to deepen your expertise in large language model applications, system design, and human-AI interaction—while learning how fast-moving AI companies operate from the inside. You’ll gain hands-on exposure to the latest model capabilities, contribute to internal experimentation, and help translate cutting-edge ideas into real-world tools.

Requirements

• 3+ years of experience in a product-oriented software engineering role.
• A strong foundation in Typescript, React, NextJS, and NodeJS.
• Experience working in fast-paced environments with a track record of rapid learning and iteration.
• Interest in research, technical writing, or contributing to knowledge-sharing within a team.

Nice To Haves

• experience with large language models, prompt engineering, or AI infrastructure.

Responsibilities

• Design, build, and iterate on fullstack systems that power AI agents from concept to deployment.
• Research and evaluate new approaches to agent orchestration, prompting strategies, and model alignment.
• Collaborate with product, design, and engineering teams to improve UX and usability for non-technical users.
• Share learnings, document findings, and contribute to the evolution of internal best practices.
• Participate in peer reviews, brainstorming sessions, and technical deep dives with our global team.

What This Job Offers

• Job Type: Full-time
• Career Level: Mid Level
• Education Level: No Education Listed
• Number of Employees: 101-250 employees