Senior Full Stack Engineer

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.
Primary Responsibilities:

• Build and lead development of AI agents using Python, LangChain/LangGraph, and advanced protocols like ReACT or ReWOO, RAG, A2A
• Design and develop scalable UI components and intelligent chatbots using React, Nextjs, TypeScript/JavaScript, HTML, CSS
• Implement Generative UI patterns and integrate LLM-driven interactions for enhanced user experience
• Ensure responsive, accessible, and high-performance front-end design optimised for real-time AI interactions
• Collaborate on back-end architecture and integration with Azure services, ensuring robust and secure APIs
• Apply Jest and Cypress for UI testing and pytest for backend validation, enforcing best practices
• Optimise application performance and scalability for real-time AI workloads
• Maintain secure state management and prompt history handling aligned with enterprise security standards
• Use modern tooling (yarn, npm, Vite, Storybook) and CI/CD pipelines for efficient development workflows
• Participate in architecture discussions, lead code reviews, and mentor junior engineers
• Contribute to strategic technical decisions and roadmap planning
• 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:

• Bachelor's or Master's in Computer Science, Engineering, or related field
• 6+ years of experience in full-stack development with increasing responsibility
• Hands-on experience with AI agent frameworks, LLM integration, and Azure cloud services
• Knowledge of testing frameworks (pytest, Jest, Cypress) and quality assurance practices
• Solid understanding of responsive, accessible design and performance optimisation for real-time systems
• Familiarity with CI/CD pipelines and containerisation (Docker/Kubernetes)
• Expert proficiency in Python and front-end frameworks (React, Next.js)
• Proven ability to design scalable architectures and implement secure solutions
• Proven excellent problem-solving, debugging, and analytical skills
• Proven solid leadership, communication, and collaboration abilities

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.