Principal Data Scientist

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.

Optum is seeking a Principal Engineer to lead the design, development, and scaling of enterprise-grade AI/ML and Generative AI solutions that solve complex healthcare and business problems. This role is ideal for a hands-on technology leader who can combine deep engineering expertise with practical innovation to build secure, scalable, and production-ready systems using modern AI platforms, cloud services, and intelligent application architectures.

In this role, you will drive the engineering vision for intelligent platforms and applications powered by LLMs, RAG, agentic AI, machine learning, and cloud-native services. You will partner across product, data, architecture, and business teams to translate strategic opportunities into robust technical solutions, establish engineering standards, and ensure systems are designed for reliability, observability, responsible AI adoption, and enterprise integration.

As a Principal Engineer, you will play a critical role in shaping next-generation digital and AI capabilities at Optum by mentoring teams, influencing architectural direction, and accelerating the adoption of advanced engineering practices. Your work will directly impact how intelligent solutions are delivered across the enterprise-improving decision-making, operational efficiency, and user experience while creating meaningful value at scale.

Primary Responsibilities:

• Fine-tunes a large language model on proprietary data to improve its performance
• Developing new machine learning models from scratch
• Experiments with novel model architectures or algorithms
• Conducts and publishes research on AI models
• Research and develop cutting-edge AI models, including deep learning, reinforcement learning, and generative architectures
• Advance agentic capabilities by designing autonomous systems that can reason, plan, and interact with complex environments
• Prototype and refine novel algorithms to improve model performance, scalability, and interpretability Collaborate with cross-functional teams to translate theoretical advancements into practical enterprise applications
• Conduct rigorous experimentation and benchmarking to evaluate model efficacy and robustness
• Publish findings, contribute to open-source initiatives, and stay abreast of emerging trends in AI research
• Ensure ethical AI development by incorporating fairness, transparency, and accountability into model design
• Optimize training pipelines and infrastructure for large-scale model deployment and continuous learning
• Mentor junior researchers and contribute to the development of internal AI knowledge bases and best practices
• Partner with data engineering and product teams to integrate AI solutions into production systems
• Comply with the terms and conditions of the employment contract, company policies and procedures, and any and all directives (such as, but not limited to, transfer and/or re-assignment to different work locations, change in teams and/or work shifts, policies in regards to flexibility of work benefits and/or work environment, alternative work arrangements, and other decisions that may arise due to the changing business environment). The Company may adopt, vary or rescind these policies and directives in its absolute discretion and without any limitation (implied or otherwise) on its ability to do so

Required Qualifications:

• 12+ years of experience in software development
• 4+ years of experience delivering solutions with a focus on AI/ML
• Extensive experience implementing generative AI solutions using Open AI compatible APIs
• Hands-on experience with Azure Functions, Azure Monitor, and App Insights
• Experience with Cloud-based AI and data services
• Experience in GitHub & M365 Copilot,Deep learning frameworks such as PyTorch, TensorFlow, Scikit Learn
• Experience or knowledge in Python, Databricks, RAG, Agentic, AI Foundry, Lang Fuse
• Experience or knowledge in enterprise search, NLP, Speech AI, Vision AI, Supervised & unsupervised ML
• Experience or knowledge in Augmented Generation (RAG) techniques
• Solid understanding of RAG architecture including knowledge of vector databases and semantic search
• Advanced proficiency in Python for AI/ML and automation
• Proven expertise in Azure Document Intelligence, OCR, and Databricks
• Proven ability to lead the design and implementation of intelligent applications using Azure Open AI, LLM Gateway, and Retrieval
• Proven ability to drive end-to-end delivery of AI-powered solutions across cross-functional teams

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.