Description

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 the 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 that 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.

Note: If you feel strongly that you have what it takes for this role but don’t check 100% of the boxes—that’s okay—we encourage you to apply anyway and highlight what you can bring to the table.