Senior Full Stack Engineer Python React HYD

Requisition Number: 2356369
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 operate Python-based AI backends using async/await, type hints, and Pydantic v2 for runtime schema validation
• Implement agentic orchestration patterns (planner/worker/solver, ReACT-style loops) with LangGraph, LangChain, or equivalents, including safe tool-calling/function-calling, prompt templating/versioning, caching, and latency/token optimizations
• Integrate Azure services (managed identity/RBAC, Key Vault, AKS/Functions) and vector DBs or equivalent stores for embeddings and long-term memory, and implement scalable conversation/session storage and lifecycle handling
• Implement resiliency, safety, and governance controls such as timeouts, retries/backoff, rate limiting, circuit breakers, safe tool execution, PII masking, input/output sanitization, and correlation ID propagation
• Add observability via structured logging, OpenTelemetry traces/metrics, and production monitoring/alerting (Application Insights/Grafana/Prometheus) and help define SLIs/SLAs
• Develop React 18 + TypeScript UIs for chat, streaming responses, tool-invocation surfaces and orchestration dashboards with accessibility (WCAG/ARIA), keyboard support and performance tuning
• Contribute to CI/CD and infra-as-code practices (Docker, Kubernetes/AKS, Terraform/Bicep), support canary/blue-green deployments, and maintain automated test/quality gates for backend, frontend and LLM-specific tests (prompt regression, hallucination checks)
• Collaborate with product, security and SRE teams to implement cost accounting, policy controls and secure developer workflows in monorepo/workspace setups (Vite, yarn/pnpm, Storybook)
• 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:

• 6+ years building production full-stack systems with substantial hands-on Python and React/TypeScript experience
• Solid experience with async Python services, API design, and Pydantic v2 (or equivalent) schema validation and secure configuration/secrets handling
• Hands-on experience implementing LLM/agent solutions (LangChain, LangGraph, or custom), including tool-calling/function-calling, multi-step orchestration, and prompt/version management
• Practical experience with Azure or equivalent cloud platforms: managed identities, Key Vault, AKS/Functions, CosmosDB/Blob/Redis or equivalents and vector DBs/embeddings for RAG
• Experience with CI/CD, Docker/Kubernetes, IaC (Terraform/Bicep), and automated testing (pytest, pytest-asyncio, Jest, Cypress)
• Proven skills in observability and reliability: OpenTelemetry, structured logging, correlation IDs, SLIs/SLAs, and alerting
• Proven solid front-end skills with React 18, TypeScript, streaming UIs, component-driven development (Storybook), accessibility and performance optimization

Preferred Qualification:

• Experience working collaboratively across product, security and operations teams; familiarity with regulated environments (healthcare/finance) is a plus

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.