Senior Front-End and Agentic-UI Engineer

Your Future Evolves Here

Evolent partners with health plans and providers to achieve better outcomes for people with most complex and costly health conditions. Working across specialties and primary care, we seek to connect the pieces of fragmented health care system and ensure people get the same level of care and compassion we would want for our loved ones.

Evolent employees enjoy work/life balance, the flexibility to suit their work to their lives, and autonomy they need to get things done. We believe that people do their best work when they’re supported to live their best lives, and when they feel welcome to bring their whole selves to work. That’s one reason why diversity and inclusion are core to our business.

Join Evolent for the mission. Stay for the culture.

What You’ll Be Doing:

Job Description

Position Summary

The Senior Software Engineer leads the design, development, and deployment of complex features in the web user experience for the Evolent Platform. This role builds high-performance React and Next.js (TypeScript) features and works closely with product managers, UX designers, and other engineers to translate business needs into technical solutions.

This individual drives the technical direction of features, contributes to front-end architecture discussions and long-term planning, and mentors junior engineers to foster a culture of continuous learning and technical excellence. The role is expected to use approved AI-assisted tools to accelerate delivery and improve quality while remaining fully accountable for every result delivered.

AI-Assisted Engineering Expectations

Evolent engineers are expected to effectively leverage approved AI-assisted development and productivity tools (e.g., code assistants, copilots, automation agents, knowledge assistants, and analytics tools) to improve quality, efficiency, and innovation while maintaining accountability for all delivered work. These expectations span the full engineering lifecycle, not only code generation, including iterating with AI on solution design and architecture, evaluating alternatives, revising existing architecture, and producing design artifacts. Engineers remain responsible for validating outputs, ensuring solution quality, protecting sensitive information, and complying with security, privacy, regulatory, and Responsible AI standards.

Key Responsibilities

Design and Development

• Lead the design, development, and deployment of complex front-end features in React and Next.js, ensuring scalability, accessibility, and maintainability.
• Build Server and Client Components that follow the team’s rendering and caching standards, including read-your-writes behavior for decision forms.
• Implement backend-for-frontend (BFF) endpoints and integrate with .NET (C#) and Python (FastAPI) services, and Entra ID / OpenID Connect authentication.
• Build data-heavy screens, including large grids, PDF and document viewers, rich-text editors, and workflow wizards, using component libraries such as KendoReact or MUI.
• Collaborate closely with product managers, UX designers, and other engineers to translate business needs into technical solutions.
• Drive the technical direction of features, contributing to front-end architecture discussions and long-term planning.

Agentic User Experience

• Build streaming user interfaces (SSE) that render agent narratives, tool calls, citations, and generative UI using the Vercel AI SDK, assistant-ui, and CopilotKit over the AG-UI protocol.
• Implement human-in-the-loop flows that let reviewers approve, modify, or override agent recommendations, including Pydantic AI tool-approval interrupts.
• Implement robust handling for slow, interrupted, or failed agent calls, including retries, timeouts, resumable streams, and clear status messaging.
• Contribute to the AG-UI event contract and shared-state design with the agent team.

Engineering Excellence

• Conduct thorough coding reviews, provide constructive feedback and ensure adherence to best coding practices.
• Mentor and coach junior engineers, fostering a culture of continuous learning and technical excellence.
• Build accessible components that meet WCAG 2.1/2.2 AA and Section 508 and resolve accessibility defects.
• Write component and end-to-end tests using Vitest, React Testing Library, and Playwright.
• Identify and implement improvements to CI/CD pipelines, supply-chain controls, and OpenTelemetry instrumentation. …