Principal UI Developer

About the Role The Appointment Scheduling platform at Engageware is the front door to some of the most important moments in a customer's day — booking time with their banker, checking in at the branch, waiting in queue, or meeting virtually with a specialist. Behind those experiences sits a suite of purpose-built applications: a multi-tenant admin console, customer-facing scheduling interfaces, in-branch self-check-in kiosks, queue management and concierge tools for branch staff, and virtual channel integrations — all running at enterprise scale for leading banks, credit unions, and healthcare organizations. We're looking for a Principal UI Developer who can own this surface end-to-end. That means leading the migration of our Angular application estate to React, setting the front-end architecture and design system, owning features all the way through the API layer when needed, and bringing strong design sensibility to interfaces that have had limited dedicated design attention. This is a high-leverage role, and we expect AI tooling to be a meaningful part of how you operate — scaffolding components, generating tests, assisting with Angular-to-React migration, exploring design directions quickly — so the scope is real but so is the support. What You'll Do React Migration & Front-End Architecture - Own the migration strategy for the Appointment Scheduling front-end estate — defining how and in what sequence we move existing Angular applications (admin console, scheduling flows, kiosk, queue management, concierge) to a modern React foundation. - Establish the shared component library, design tokens, state management patterns (React Query, Zustand, or Redux Toolkit), and routing architecture that all new and migrated applications are built on. - Make pragmatic migration decisions — incremental strangler-fig patterns vs. targeted rebuilds — balancing speed, risk, and continuity for live enterprise customers. - Define the module boundaries and shared abstractions that allow Angular and React to coexist safely during the transition. Design System & Interface Quality - Own the visual and interaction language for the Appointment Scheduling platform: component library, spacing system, color tokens, typography, and interaction patterns — maintained in Storybook and connected to Figma where design work happens. - Bring design sensibility to every interface you ship. In the absence of dedicated design resources, you are the person who catches the awkward empty state, the unclear confirmation flow, the button that doesn't belong. You use AI design tools (Figma AI, v0, Claude) to explore and prototype directions quickly rather than waiting for a design brief. - Ensure all applications meet WCAG 2.1 AA accessibility standards — a non-negotiable for banking and healthcare customers with regulatory obligations. - Optimize for the full deployment surface: responsive web, touch-screen kiosks (constrained sizes, high-contrast, minimal input complexity), and staff-facing branch tablets in fast-paced environments. API Layer & End-to-End Feature Ownership - Own features end-to-end when the critical path runs through the front end: design and build the BFF (Backend for Frontend) endpoints, lightweight Spring Boot routes, and data-shaping layers the UI requires — without waiting on someone else to unblock you. - Design clean REST API contracts between front-end applications and the scheduling platform services, with clear error-handling conventions and versioning. - Collaborate with backend engineers on deeper service-layer work, contributing meaningfully to API design reviews and surfacing front-end integration requirements early. - Handle the full stack of front-end reliability concerns: caching strategies, optimistic UI, graceful degradation, and real-time event handling (WebSockets, SSE) where the scheduling experience demands it. Test-Driven Development & Quality - Champion test-driven development across all front-end work: