Senior Full Stack Engineer, AI Platform

Geisinger

3d • Remote

About The Position

Geisinger is operationalizing AI at scale, moving past pilots into a portfolio of production AI capabilities serving over 70 programs across clinical care, operations, the health plan, and pharmacy. This role is crucial for building the internal applications, such as dashboards, evaluation tools, and developer portals, that program teams, governance stakeholders, and platform engineers use daily. The Senior Full Stack Engineer is responsible for the end-to-end product quality of all user-facing applications developed by the AI Platform, encompassing everything from the design system and component library to backend-for-frontend APIs, telemetry, role-based access, and load-time budgets. This position ensures that internal AI tooling is robust and reliable, directly impacting the pace at which teams can access platform data, configure capabilities, and onboard themselves. The ideal candidate will treat internal applications as a primary product surface and have strong opinions on what constitutes high-quality user experiences.

Requirements

• 5+ years of full stack engineering experience shipping production web applications.
• At least 2 years as the senior frontend voice on a team or product.
• Deep proficiency in modern React (hooks, context, suspense, performance patterns) and its ecosystem.
• Hands-on experience designing or substantially evolving a shared component library or design system used by multiple applications.
• Strong fluency in Python and FastAPI (or comparable Python web framework experience) for backend-for-frontend work.
• Demonstrated ownership of accessibility (WCAG 2.1 AA) as a primary engineering concern.
• Experience implementing role-based access controls and permission-aware views in applications.
• Proficiency in testing practices: unit, integration, and E2E with Playwright or Cypress.
• Experience instrumenting applications with usage telemetry and using that data to inform product decisions.
• Strong written communication skills for technical specs, design system documentation, and API contracts.
• Bachelor's degree in Computer Science, a related technical field, or equivalent professional experience.
• Minimum of 14 years of relevant experience (combination of work experience and degree obtained is considered).

Nice To Haves

• Experience as the founding or lead frontend engineer on an internal-tools or platform-engineering team.
• Experience with Mantine, MUI, or comparable enterprise component libraries.
• Production experience with OpenTelemetry on the frontend or comparable observability tooling.
• Familiarity with healthcare data, clinical workflows, or regulated-industry environments.
• Experience integrating with enterprise SSO / IdP systems as a consumer.
• Exposure to AI/ML application interfaces (model evaluation tooling, monitoring dashboards, LLM application UX).

Responsibilities

• Own the frontend architecture and the shared design system/component library for consistency in visual and interaction design across all AI Platform applications.
• Develop RBAC-aware interfaces, ensuring users see appropriate data and controls based on their roles (program teams, governance stakeholders, leadership, platform engineers).
• Manage the backend-for-frontend layer, including API patterns, data contracts with MLOps, and UI-backend integration points.
• Define and implement the application-level testing strategy, including unit, integration, and end-to-end suites for automated deployment verification.
• Instrument applications for usage telemetry and analytics, tracking adoption, feature engagement, error rates, and load times to inform the platform roadmap.
• Optimize frontend performance through bundle optimization, caching, lazy loading, and managing load-time budgets to maintain user trust.
• Define and enforce UX quality gates to ensure a high standard for all shipped applications.
• Build accessibility into the design system from the outset.
• Collaborate with MLOps engineers on API contracts, feature requirements, and versioning.
• Coordinate with the Sr. Platform Engineer on deployment targets, CDN, environment configuration, IDP provisioning, and authentication infrastructure.
• Align with the Sr. Software Engineer (Integration) on shared API design patterns, authentication flows, and RBAC implementation.
• Partner with the AI Platform Team Lead on roadmap, priorities, and architecture reviews.

Benefits

• Healthcare benefits for full time and part time positions from day one, including vision, dental and domestic partners.
• Atmosphere of collaboration, cooperation and collegiality.

What This Job Offers

• Job Type: Full-time
• Career Level: Senior
• Number of Employees: 5,001-10,000 employees