Lead Engineer, Applied AI at Circle

About the role

The Applied AI team at Circle is at the forefront of leveraging AI to drive innovation across our company. We’re looking for a Lead Engineer, Applied AI to spearhead the development of AI solutions that enhance user experiences across our platform, both internally and externally. You’ll also lead and manage the Applied AI engineering team, help organize & coordinate work, and serve as a people manager.

If you’re passionate about working on real production use cases of large language models (LLMs) and want to contribute to transformative AI applications, this role is for you.

What you’ll be doing

• Ship full-stack AI projects end-to-end – exciting projects such as AI Agents, Retrieval-Augmented Generation (RAG), Structured Extraction, internal tooling for customer-facing teams, and build infrastructure for LLM inference.
• Own the end-to-end architecture and technical strategy for AI solutions.
• Hire, onboard, and lead a small team of senior engineers, supporting their growth and ensuring high-impact execution.
• Improve processes, tools, and systems to scale AI solutions across Circle.
• Optimize AI infrastructure for performance, reliability, and cost-efficiency.
• Help us stay up-to-date with cutting-edge AI research, techniques, and tools.

What you’ll need to be successful

• 5+ years experience working as a full-stack engineer on complex web applications.
• Strong proficiency in Ruby on Rails, MySQL/Postgresql, ReactJS. Familiarity with both frontend and backend is necessary, but a high degree of proficiency in both is not a requirement.
• Strong proficiency in at least one programming language commonly used for AI development (Python, JavaScript, TypeScript).
• You have deployed at least one AI Agent to production, with a deep understanding of the entire development lifecycle — from initial concept to final deployment with customer feedback loops.
• You have experience leading a team of engineers, especially in growth-focused environments.
• Hands-on experience with AI frameworks and tools, such as OpenAI, Anthropic, Hugging Face, LangChain, and vector databases.
• Strong understanding of NLP, ML, and LLM fundamentals – including modern LLM technologies, RAG, and prompt engineering techniques.
• A desire to work in an environment which values speed of iteration and individual autonomy, while also embracing personal accountability and the ability to collaborate effectively as part of a dynamic team.

Bonus points

• You have contributed to open-source AI/ML projects.

$160,000 – $180,000 USD per year

The cash compensation range shown is a starting point. In addition to equity, benefits and perks, your cash compensation is subject to an annual review and increase on a once per year basis.

The fun stuff

• Fully remote: work from anywhere in the world!
• Autonomy and trust to do your job: we care about outcomes over everything else.
• Paid time away: all employees are given 35 days of PTO annually. We also offer a paid sabbatical after 5 years.
• Generous U.S. benchmarked compensation and startup equity no matter where you are in the world.*
• Awesome medical coverage with 100% coverage for you and your family, or medical reimbursement options where applicable!
• Parental leave for parents expanding their family, or just starting one.
• Home office stipend to help you get started.
• Learning & development stipend to help you level up your professional skills.
• Annual bonus potential for roles that don’t already receive variable income or commission.
• Company retreats: Twice a year, the Circle team gets together for a fully paid company retreat in incredible places around the world! We’ve had past retreats in Colombia, Portugal, and Mexico, with more planned on the horizon.

Method of Application