Senior Data Scientist

Requisition Number: 2338441
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 seeking an experienced Data Scientist with 7-11 years of strong hands-on expertise in building, deploying, and optimizing machine learning and GenAI solutions. The ideal candidate must have deep proficiency in Python-based ML workflows, big data computing frameworks, and modern cloud/ML tools. Experience with LLMs, embeddings, and advanced NLP is essential.
Primary Responsibilities:

• Build, optimize, and productionize ML and GenAI models using Python, Spark, and cloud-based ML platforms
• Integrate LLM capabilities (APIs, agents) into enterprise applications and end-to-end data workflows
• Develop and maintain scalable data pipelines for model training, validation, and inference using Spark/Databricks
• Implement RAG pipelines, embedding-based search, and LLM-driven text generation
• Conduct experimentation, model evaluation, A/B testing, and performance tuning using tools like MLflow
• Collaborate closely with product, engineering, and platform teams to ship production-grade AI features
• Follow best practices in version control, CI/CD, testing, deployment, and documentation
• Provide technical mentorship to junior data scientists and contribute to solution design discussions
• 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:

• Master's degree in Data Science, Computer Science, or related field
• Solid experience in AI/ML, big data technologies, and cloud platforms (Azure preferred)
• Solid hands-on experience in Python using pandas, NumPy, and scikit-learn
• Practical experience working with cloud platforms such as Azure, AWS, or GCP
• Experience building and optimizing RAG (Retrieval Augmented Generation) pipelines
• Proficiency in Python, SQL, Spark, and Agile/Scrum
• Solid knowledge of BERT, Transformers, and embeddings for NLP.
  Hands-on experience in LLM text generation using APIs and agent frameworks
• Solid understanding of Git, MLflow, and cloud ML services for model deployment and tracking
• Proficiency using Jupyter or cloud-based ML development environments
• Proven expertise in Big Data processing using PySpark, Spark, and Databricks
• Proven ability to develop classification models using BERT or Transformer-based architectures

Preferred Qualifications:

• Knowledge of healthcare claims, payment integrity, and compliance frameworks
• Tree-based ML models (XGBoost, Random Forest), regression/classification
• Time series modelling
• Clustering techniques
• Model optimization & hyperparameter tuning
• Basic statistical analysis
• Data cleaning, EDA, and feature engineering

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.