Senior Fullstack Engineer — AI Agents & LLM Systems

11x AI Inc.; Seattle (WA); On-site; USD 180,000 - 250,000; Full time

Job summary

11x AI Inc. in Seattle is seeking a senior fullstack engineer who loves applied research and cross-functional collaboration.

You’ll prototype, build, and scale autonomous digital workers, leveraging modern web tech and AI systems to deliver real‑world tools. You’ll work closely with engineering leadership and AI partners on model‑driven architectures, human‑AI interaction, and rapid iteration in a fast‑paced environment, with ample opportunities to contribute to knowledge sharing and internal

Qualifications

• 6+ years of experience in a product‑oriented software engineering role.
• 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.

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.

Skills

Typescript

React

NextJS

NodeJS

Fast-paced environments

Technical writing

Tools

AI infrastructure

Prompt engineering

Job description

11x AI Inc. in Seattle is seeking a senior fullstack engineer who loves applied research and cross-functional collaboration.

You’ll prototype, build, and scale autonomous digital workers, leveraging modern web tech and AI systems to deliver real‑world tools. You’ll work closely with engineering leadership and AI partners on model‑driven architectures, human‑AI interaction, and rapid iteration in a fast‑paced environment, with ample opportunities to contribute to knowledge sharing and internal