Senior AI/ML Engineer

Requisition Number: 2385163
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 diversity and inclusion, talented peers, comprehensive benefits and career development opportunities. Come make an impact on the communities we serve as you help us advance health equity on a global scale. Join us to start Caring. Connecting. Growing together.
As a Senior AI Engineer, you will design, build and operate production AI agents grounded in governed enterprise healthcare data. You will use Snowflake Cortex, Python, large language models, retrieval, semantic models and tool-based orchestration to deliver reliable conversational and workflow-driven AI solutions. You will own the AI engineering lifecycle-from use-case translation and agent design through evaluation, deployment, monitoring and continuous improvement-while applying solid privacy, security and responsible AI controls.
Careers with Optum offer flexible work arrangements and individuals who live and work in the Republic of Ireland will have the opportunity to split their monthly work hours between our Dublin or Letterkenny office and telecommuting from a home-based office in a hybrid work model.
What you will do:

• Design and productionize LLM-powered solutions using Azure OpenAI - including retrieval-augmented generation, prompt and context engineering, and agentic workflows grounded in enterprise healthcare data
• Designing agent instructions, tools and orchestration flows
• Building guardrails, validation and fallback behaviour
• Integrating agents with APIs, applications and enterprise services
• Troubleshooting retrieval, semantic-model, prompt and tool-selection issues
• Build applied AI and generative AI solutions that support data governance, quality, and compliance across the data lifecycle
• Orchestrate and schedule data workflows using tools such as Apache Airflow and Azure Data Factory, ensuring reliability, observability, and cost efficiency
• Implement data governance, data quality, lineage, schema drift detection, and access-control/masking practices to keep sensitive and regulated data secure and compliant
• Develop evaluation, throttling, and reliability patterns for LLM systems - measuring accuracy, groundedness, cost, and latency in production
• Partner with data science, product, architecture, security, and governance stakeholders to turn use cases into workable, well-documented solutions
• Apply responsible data and AI practices, including privacy, safety, bias awareness, human-in-the-loop review, and traceability for sensitive and regulated data
• Contribute to team engineering standards through code review, documentation, and reusable components, and share knowledge with peers

You will 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 providing development for other roles you may be interested in.
What you will bring:

• Bachelor's degree in a relevant field, or equivalent professional experience
• Proven experience building and operating production data pipelines and platforms within public cloud environments
• Demonstrated advanced proficiency in SQL and Python, with experience using data engineering and data processing libraries
• Proven hands-on experience with modern cloud data platforms such as Snowflake and Databricks
• Proven hands-on experience developing Generative AI applications using large language models, including Azure OpenAI, LLM gateways, prompt engineering, retrieval-augmented generation (RAG), embeddings, and vector search
• Proven hands-on experience designing, deploying, and supporting production large language model (LLM) and agentic AI solutions, including retrieval, tool integration, evaluation, monitoring, and failure handling
• Proven experience integrating LLMs into Databricks, Snowflake, or similar data platforms to support production use cases
• Proven experience designing semantic models and business-friendly data abstractions to support natural language analytics and AI agents
• Demonstrated working knowledge of data modeling, data preparation, and data pipeline concepts, with experience working with large datasets
• Proven experience with DataOps practices, including version control, automated testing, CI/CD, and production monitoring
• Demonstrated understanding of cloud security, identity and access management, data governance, and privacy principles for sensitive data
• Proven ability to collaborate with technical and non-technical stakeholders and communicate data and AI concepts, trade-offs, and limitations effectively

Other useful skills and experience include:

• Proven experience developing AI solutions using Snowflake Cortex, Cortex Search, Cortex Analyst, semantic models, or similar AI platforms
• Proven experience with data governance tooling, data cataloging, lineage, schema drift detection, and data masking and classification
• Proven experience with Snowflake performance tuning and cost optimization, including clustering, warehouse sizing, and query profiling
• Demonstrated solid understanding of classical machine learning, including feature engineering, model selection, training, tuning, and validation
• Proven experience applying responsible AI, governance, and security controls within sensitive or regulated data environments
• Proven experience within the healthcare industry

What We Offer:

• Opportunities for professional development
• Inclusive and supportive team culture
• Key benefits: Private health insurance, wellness programs, matching pension contribution, lunch provided by the company, training opportunities, employee donations matching and others

Please note you must currently be eligible to work and remain indefinitely without any restrictions in the country to which you are making an application. Proof will be required to support your application.
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.
Diversity creates a healthier atmosphere: Optum is an Equal Employment Opportunity employer and all qualified applicants will receive consideration for employment without regard to gender, civil status, family status, sexual orientation, disability, religion, age, race, and membership of the Traveller community, or any other characteristic protected by law. Optum is a drug-free workplace. © 2026 Optum Services (Ireland) Limited. All rights reserved.
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