Sr AI/ML Engineer - Hybrid in MN or DC - Remote elsewhere

Requisition Number: 2343638
Transform Healthcare Through AI Innovation at Optum
Optum is a global organization delivering care, powered by data and technology, to help millions of people live healthier lives. At Optum.ai, we are not just witnessing the AI transformation in healthcare-we are leading it. Our mission is clear: to simplify healthcare with AI, turning insight into action at a scale few organizations in the world can match.
As part of the Optum.ai team, you'll work at the intersection of cutting-edge artificial intelligence and real-world healthcare impact. From reducing administrative burden for providers to anticipating patient needs and improving access to quality care, your work will help solve some of healthcare's most complex challenges-and directly improve health outcomes for millions of people.
You'll collaborate with world-class talent across data science, engineering, product, and healthcare domains, backed by the reach and stability of Optum and UnitedHealth Group. Here, responsible innovation matters. So do comprehensive benefits, meaningful career growth, and the opportunity to make a tangible difference-advancing health equity and creating a simpler, more connected healthcare experience for everyone.
This is more than a job. It's a chance to shape the future of healthcare through the transformative power of AI.
Join us to start Caring. Connecting. Growing together.
Optum AI is UnitedHealth Group's enterprise AI team. We are AI/ML scientists and engineers with deep expertise in AI/ML engineering for healthcare. We develop AI/ML solutions for the highest impact opportunities across UnitedHealth Group businesses including UnitedHealthcare, Optum Financial, Optum Health, Optum Insight, and Optum Rx. In addition to transforming the healthcare journey through responsible AI/ML innovation, our charter also includes developing and supporting an enterprise AI/ML development platform.
As a Senior AI/ML Engineer, you will design and build advanced machine learning and generative AI solutions that power enterprise applications and decision systems. You will work on large language models, retrieval-augmented generation pipelines, and agent-based AI systems while ensuring production-grade reliability, performance, and safety.
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 deploy generative AI and NLP solutions using transformer-based architectures for enterprise use cases such as search, summarization, extraction, conversational AI, and decision support
• Develop and fine-tune large language model (LLM) applications using commercial and open-source models such as OpenAI, Anthropic/Claude, Gemini, LLaMA, or Mistral
• Design and implement retrieval-augmented generation (RAG) pipelines including document ingestion, chunking strategies, embedding generation, and vector database integration
• Build agentic AI systems including single-agent and multi-agent workflows capable of tool use, reasoning, planning, and autonomous task execution
• Implement evaluation and monitoring frameworks for generative AI systems including hallucination detection, bias monitoring, and human-in-the-loop evaluation
• Develop safety and governance controls for AI systems including prompt hardening, policy enforcement, and responsible AI guardrails
• Productionize AI/ML pipelines using CI/CD, testing, monitoring, and observability best practices in cloud-native environments
• Collaborate with product, platform, and data science teams to translate requirements into scalable AI solutions

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:

• 5+ years of experience in machine learning, AI engineering, or applied data science including development of production ML systems
• 5+ years of experience developing Python-based ML systems using frameworks such as PyTorch, TensorFlow, or Hugging Face
• 3+ years of experience building Generative AI or LLM applications including prompt engineering, model fine-tuning, and LLM API integrations
• 2+ years of experience designing retrieval-augmented generation (RAG) systems and vector search pipelines
• 1+ year of experience building agentic AI systems including tool-calling, planning frameworks, or multi-agent workflows
• 1+ year of experience using AI-assisted development or 'vibe coding' tools such as Codex, Claude Code, Cursor, Windsurf, or similar tools

Preferred Qualifications:

• Experience with LLM orchestration frameworks such as LangChain, LlamaIndex, or Semantic Kernel
• Experience optimizing LLM latency, cost, and performance in production environments
• Experience deploying AI systems on cloud platforms such as AWS, Azure, or GCP
• Experience working in regulated environments with responsible AI governance requirements

*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 $91,700 to $163,700 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.
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