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

Optum Tech is a global leader in health care innovation. Our teams develop cutting-edge solutions that help people live healthier lives and help make the health system work better for everyone. From advanced data analytics and AI to cybersecurity, we use innovative approaches to solve some of health care's most complex challenges. Your contributions here have the potential to change lives. Ready to build the next breakthrough? Join us to start Caring. Connecting. Growing together.

Come build the AI foundation behind SGS, a modern platform where multi agent systems can reason, plan, and safely connect to enterprise tools to turn conversations, documents, and network signals into action. In this role, you will own the architecture for the capabilities customers feel every day, including real time voice translation, voice based assessments, and call quality audits that help teams respond faster and follow the right procedures. You will also advance Document AI and our Virtual Investigator to accelerate intake, surface risk early, and turn complex investigative questions into clear, explainable answers. On the fraud side, you will combine real time ML with graph analytics to detect emerging hotspots, uncover collusive networks, and stop improper payments before they happen, then translate that intelligence into AI generated insights and KPI visibility leaders can use immediately. You will set the technical direction for orchestration and governance on Azure, raise engineering standards across product lines, and mentor a globally distributed team that ships to production. If you want deep ownership, high stakes impact, and the chance to define how agentic AI operates at scale, you will thrive here.

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:

• AI Engineering Projects: Design and implement multi-agent AI systems that use LLMs, memory, and tools to reason, plan, and act autonomously
• Function Calling & Orchestration: Build agent-based solutions that use function calling, dynamic tool integration, and orchestration frameworks like LangChain, AutoGen, and Semantic Kernel
• Modular Agent Design: Leverage standards like Model Context Protocol (MCP) to define reusable, secure, and composable tool interfaces
• Voice-Driven Interfaces: Develop voice-first AI agents using ASR (e.g. Whisper, Azure Speech), multi-turn conversation orchestration, and high-quality TTS
• RAG & Memory Pipelines: Design and maintain Retrieval-Augmented Generation (RAG) pipelines using vector databases and Azure Cognitive Search
• Fraud Detection & ML Ops: Contribute to anomaly detection and fraud modeling efforts, including ML model training, real-time inference, and pipeline optimization
• Cloud-Native AI Deployment: Build, deploy, and monitor scalable AI services on Azure, including Azure OpenAI, Functions, Service Bus, Cosmos DB, and related tools
• Agentic UX & AI as an Interface: Drive innovation in agentic user experiences, enabling AI to operate external tools and services securely on behalf of users
• Mentorship & Collaboration: Review PRs, mentor junior engineers, and collaborate across India and US time zones in a distributed, agile environment

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:

• Undergraduate degree or equivalent experience
• 5+ years of total engineering experience   
• 5+ years of experience with AI/ML product engineering roles
• 5+ years of experience with Python development; proficiency with ML frameworks like PyTorch, scikit-learn, Hugging Face
• 5+ years of experience with Azure AI stack (Azure OpenAI, Cognitive Services, Functions, Service Bus, Cognitive Search)
• 5+ years of experience with fraud detection models or anomaly detection pipelines
• 3+ years of experience with voice systems, including ASR, TTS, and real-time audio/telephony integration
• 2+ years of experience with LLM integration, tool calling, prompt engineering, and context-aware task execution
• 2+ years of experience building and shipping LLM-powered or autonomous agent systems in production
• 2+ years of hands-on work experience with retrieval techniques (RAG, semantic search, embeddings) and vector DBs
• Demonstrated track record of contributing to robust, testable, and scalable engineering systems

Preferred Qualifications: 

• LLM evaluation and regression testing experience: experience building automated evaluation harnesses for LLM and agent workflows, including golden datasets, offline and online testing, and measurable quality metrics (for example task success rate, groundedness, or human review agreement) 
• Responsible AI and adversarial testing experience: Hands on experience with prompt injection and data exfiltration testing, safety reviews, and implementing guardrails to reduce hallucinations and unsafe outputs in production 
• Production observability for agents: Proven implemented end to end monitoring for agentic systems, including distributed tracing, tool call success rates, latency and error budgets, and token and cost telemetry with actionable alerting 
• Security for tool calling and AI systems experience: Proven designed secure patterns for tool enabled agents, including least privilege access, secrets management, and policy based controls for tool/API execution (for example OAuth scopes, managed identity, and audit logging) 
• Platform scale and efficiency experience: Proven ability to optimize LLM or voice system performance and cost using techniques such as caching, batching, streaming responses, rate limiting, model routing, and fallback strategies

*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 $120,118 to $214,496 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.