Principal AI Engineer: LLMs & Agentic Systems Lead

FactSet; Norwalk (CT); On-site; USD 180,000 - 235,000; Full time

Benefits offered by this job

Health insurance

Employee stock purchase program (edic)

Flexible work accommodations

Job summary

FactSet is seeking a Principal Software Engineer to design, build, and ship AI-powered products that leverage LLMs and agentic technologies. You will lead engineering standards, mentor teammates, and shape the direction of the AI product portfolio while delivering production-grade features.

You’ll work on orchestration, tool usage, retrieval, evaluation, and observability, using Claude Code and modern AI DLC practices.

Qualifications

• Bachelor’s degree in computer science or relevant field.
• 8-10+ years of extensive software development, testing, and deployment experience.
• Hands-on experience building and deploying applications using LLMs and agentic technologies (prompt engineering, RAG, function/tool calling, agent orchestration frameworks).
• Familiarity with AI coding assistants such as Claude Code and the AI-driven development lifecycle (planning through deployment).
• Strong software architecture, scalable and observable systems, and proven code-review mentorship skills.

Responsibilities

• Design, build, test, and deploy production-grade LLM- and agentic-powered software.
• Lead code and design reviews and set AI development standards across the team.
• Mentor engineers on AI patterns, agent design, and use of AI tooling.
• Collaborate with product/design/architecture peers to scope and deliver AI features.
• Diagnose AI-specific issues including non-determinism, hallucinations, and prompt/tool failures.

Skills

LLMs and agentic technologies

Prompt engineering

RAG

Function/tool calling

Agent orchestration frameworks

Claude Code

AI-driven development lifecycle

Software architecture

Code reviews

Mentoring engineers

Effective communication

Education

Bachelor’s degree in computer science or relevant

Tools

Claude Code

MCP servers

Job description

FactSet is seeking a Principal Software Engineer to design, build, and ship AI-powered products that leverage LLMs and agentic technologies. You will lead engineering standards, mentor teammates, and shape the direction of the AI product portfolio while delivering production-grade features.

You’ll work on orchestration, tool usage, retrieval, evaluation, and observability, using Claude Code and modern AI DLC practices.