Senior Fullstack Software Engineer, AI Agents

Senior Fullstack Software Engineer, AI Agents

Apply for the Senior Fullstack Software Engineer, AI Agents role at 11x
.

At 11x, we’re building autonomous digital workers that handle routine work end-to-end, freeing humans to focus on creating, innovating, and building meaningful relationships. We’re one of the world’s fastest‑growing AI companies, achieving a 20× increase in ARR and raising $75M+ from leading investors including a16z and Benchmark. The 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.

• 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.

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

• Seniority level:
  Mid‑Senior level
• Employment type:
  
  Full‑time
• Job function:
  Engineering and Information Technology
• Industries:
  Software Development

Canada base salary range: CAD $180,000 – $225,000

Seattle base salary range: USD $150,000 – $250,000

Final offer will be based on a variety of factors, including role level, relevant experience, skills, and job‑related expertise.

11x is an equal opportunity employer and does not discriminate on the basis of race, gender, sexual orientation, gender identity/expression, national origin, disability, age, genetic information, veteran status, marital status, pregnancy or related condition, or any other basis protected by law.

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