Principal AI Engineer: Lead Production LLMs & AI Platform

Harrington Starr; Boston (MA); On-site; USD 180,000 - 260,000; Full time

Job summary

Harrington Starr in Boston is seeking a Principal AI Engineer to shape the next generation of AI capabilities. This hands-on technical leadership role involves designing and deploying production AI systems, architecting scalable RAG pipelines, and building AI APIs in Python.

You will influence architecture, drive model evaluation, and mentor engineers in a fast-paced capital markets tech environment. The ideal candidate has built and deployed production LLM applications, with strong experience

Qualifications

• Experience building and deploying production AI systems at scale.
• Strong background with RAG, AI agents and modern AI frameworks.
• Experience with vector databases, cloud platforms and scalable distributed systems.
• Track record of owning complex technical projects from concept through production.
• Previous experience in financial services or capital markets is a plus.

Responsibilities

• Design, build and deploy production-grade AI applications.
• Architect scalable RAG pipelines and agentic workflows.
• Build reliable AI APIs and backend services using Python.
• Drive model evaluation and prompt optimisation.
• Partner with engineering leadership on architecture and strategy.
• Mentor engineers and establish best practices across the AI function.

Skills

Production AI systems

RAG pipelines

AI agents

LLM-powered services

Python back-end

Model evaluation

System performance

Architecture leadership

Mentoring engineers

Vector databases

Cloud platforms

Distributed systems

Education

Bachelor’s degree in a technical field

Tools

Python

Vector databases

Cloud platforms

Job description

Harrington Starr in Boston is seeking a Principal AI Engineer to shape the next generation of AI capabilities. This hands-on technical leadership role involves designing and deploying production AI systems, architecting scalable RAG pipelines, and building AI APIs in Python.

You will influence architecture, drive model evaluation, and mentor engineers in a fast-paced capital markets tech environment. The ideal candidate has built and deployed production LLM applications, with strong experience