Lead AI Engineer - Remote

Optum is a global organization that delivers care, aided by technology to help millions of people live healthier lives. The work you do with our team will directly improve health outcomes by connecting people with the care, pharmacy benefits, data and resources they need to feel their best. Here, you will find a culture guided by inclusion, talented peers, comprehensive benefits and career development opportunities. Come make an impact on the communities we serve as you help us advance health optimization on a global scale. Join us to start Caring. Connecting. Growing together.

We are looking for a Senior GenAI Developer with solid hands-on expertise in both open source and AWS Generative AI stacks. You will design and build production-ready RAG pipelines, agentic AI workflows, and knowledge base chatbots. You will work closely with architects and business stakeholders to deliver accurate, low-hallucination, observable AI solutions at enterprise scale.

You'll enjoy the flexibility to work remotely * from anywhere within the U.S. as you take on some tough challenges. For all hires in the Minneapolis or Washington, D.C. area, you will be required to work in the office a minimum of four days per week.

Primary Responsibilities:

• Design and build production-grade RAG pipelines using LangChain and LangGraph for stateful agentic workflows
• Develop and maintain knowledge base chatbots with semantic search, source attribution, and multi-turn conversation memory
• Implement advanced retrieval strategies - Hybrid Search (vector keyword), HyDE, and Hierarchical / Small-to-Big chunking
• Build and manage multi-agent orchestration architectures with Agentic RAG patterns (Corrective RAG, Self-RAG)
• Integrate LLMs (Claude, GPT-4o, Llama 3, Mistral) via API and open-source hosting (Fireworks AI, Groq)
• Design and operate vector databases - Pinecone, Weaviate, or PGVector - for semantic knowledge storage
• Build AWS Bedrock-based solutions using Bedrock Agents, Knowledge Bases, and Guardrails
• Set up evaluation frameworks using Ragas (faithfulness, relevance scoring) and maintain Golden Datasets for CI/AI testing
• Implement LLM observability using LangSmith or Phoenix - trace calls, debug hallucinations, monitor costs
• Apply PII redaction pipelines on ingested documents and enforce data security using Model Context Protocol (MCP)
• Deploy AI backends using FastAPI and Docker with OpenTelemetry for system-wide monitoring
• Collaborate with Solution Architects to produce HLDs, LLDs, and developer-facing documentation for AI components

You'll be rewarded and recognized for your performance in an environment that will challenge you and give you clear direction on what it takes to succeed in your role as well as provide development for other roles you may be interested in.

Required Qualifications:

• Bachelor's or Master's degree in Computer Science, Artificial Intelligence, Data Science, or a related field
• 8 years of overall software / AI engineering experience
• 2 years of direct hands-on experience building and deploying GenAI / LLM-based applications in production
• Solid Python development skills - primary language for AI engineering work
• Demonstrated portfolio or project experience with RAG pipelines, vector databases, and agentic architectures
• Driver's License and access to reliable transportation

Preferred Qualifications:

• AWS Certified AI Practitioner (AIF-C01) or Generative AI Developer (AIP-C01) certification
• AWS Certified Cloud Practitioner or Developer Associate
• AI/ML Specialty
• Experience with Graph RAG for complex entity-relationship knowledge bases
• Experience with Semantic Kernel as an alternative orchestration framework
• Knowledge of Human-in-the-Loop systems - expert review/voting UI for AI answer correction
• Familiarity with fine-tuning open-source LLMs (LoRA / QLoRA) on domain-specific datasets
• Exposure to Amazon Connect integration with Bedrock Agents via Lex V2 for contact centre AI

*All employees working remotely will be required to adhere to UnitedHealth Group's Telecommuter Policy

Pay is based on several factors including but not limited to local labor markets, education, work experience, certifications, etc. In addition to your salary, we offer benefits such as, a comprehensive benefits package, incentive and recognition programs, equity stock purchase and 401k contribution (all benefits are subject to eligibility requirements). No matter where or when you begin a career with us, you'll find a far-reaching choice of benefits and incentives. The salary for this role will range from $145,500 - $249,500 annually based on full-time employment. We comply with all minimum wage laws as applicable.

Application Deadline: This will be posted for a minimum of 2 business days or until a sufficient candidate pool has been collected. Job posting may come down early due to volume of applicants.

At UnitedHealth Group, our mission is to help people live healthier lives and make the health system work better for everyone. We believe everyone-of every race, gender, sexuality, age, location and income-deserves the opportunity to live their healthiest life. Today, however, there are still far too many barriers to good health which are disproportionately experienced by people of color, historically marginalized groups and those with lower incomes. We are committed to mitigating our impact on the environment and enabling and delivering equitable care that addresses health disparities and improves health outcomes - an enterprise priority reflected in our mission.

UnitedHealth Group is an Equal Employment Opportunity employer under applicable law and qualified applicants will receive consideration for employment without regard to race, national origin, religion, age, color, sex, sexual orientation, gender identity, disability, or protected veteran status, or any other characteristic protected by local, state, or federal laws, rules, or regulations.

UnitedHealth Group is a drug-free workplace. Candidates are required to pass a drug test before beginning employment.

Salary : $145,500 - $249,500