Senior UI/UX Developer

Job Description Company Overview Milestone Technologies is a global IT managed services firm that partners with organizations to scale their technology, infrastructure and services to drive specific business outcomes such as digital transformation, innovation, and operational agility. Milestone is focused on building an employee-first, performance-based culture and for over 25 years, we have a demonstrated history of supporting category-defining enterprise clients that are growing ahead of the market. The company specializes in providing solutions across Application Services and Consulting, Digital Product Engineering, Digital Workplace Services, Private Cloud Services, AI/Automation, and ServiceNow. Milestone culture is built to provide a collaborative, inclusive environment that supports employees and empowers them to reach their full potential. Our seasoned professionals deliver services based on Milestone's best practices and service delivery framework. By leveraging our vast knowledge base to execute initiatives, we deliver both short-term and long-term value to our clients and apply continuous service improvement to deliver transformational benefits to IT. With Intelligent Automation, Milestone helps businesses further accelerate their IT transformation. The result is a sharper focus on business objectives and a dramatic improvement in employee productivity. Through our key technology partnerships and our people-first approach, Milestone continues to deliver industry-leading innovation to our clients. With more than 3,000 employees serving over 200 companies worldwide, we are following our mission of revolutionizing the way IT is deployed. Job Overview Job Description Job Overview We're hiring a Senior UI/UX Developer to design and build user interfaces for an AI-first, data-centric platform. You'll own the end-to-end experience for chat/assistive workflows, human-in-the-loop (HITL) approvals, and explainability views (sources, rationales). The ideal candidate blends product sense with strong frontend engineering, accessibility, and design-system rigor-shipping fast, usable, and secure interfaces. Key Responsibilities - Product UX & Flow Design: Define user journeys for discovery answer approval action; craft low/high-fidelity prototypes and interaction specs. - HITL & Explainability UI: Build approval modals and review panes that summarize intent, scope, impacted systems, and sources/subgraph rationale; ensure clear confirm/reject flows with auditability. - Chat & Workspace Interfaces: Implement responsive chat/workbench UI, message streaming, citations, error states, and retries; support role-based views and guardrail feedback. - Component Library & Design System: Establish reusable components, tokens, theming, and documentation; maintain consistency, accessibility, and performance across surfaces. - Frontend Engineering: Ship production SPAs with robust state/data fetching, routing, optimistic updates, and skeleton/loading patterns. - Accessibility & Quality: Enforce WCAG-aligned semantics, keyboard navigation, focus management, and contrast; write unit/e2e tests and visual regressions. - Telemetry & Experimentation: Instrument UX metrics (latency, drop-offs), feature flags, and A/B hooks; partner on dashboards for usability and adoption. - Collaboration & Delivery: Work with analysts on acceptance criteria, with backend/AI engineers on contracts, and with security on SSO/entitlement UX. Participate in code reviews and release rituals. Required Skills - Frontend Stack: Expert in React + TypeScript, modern state/data tools, and routing. - Styling & Systems: CSS expertise (Flex/Grid), component libs and utility frameworks (e.g., Tailwind, MUI/Ant), design tokens, theming, and responsive design. - API Integration: Strong REST/WebSocket/SSE integration, schema-driven development (OpenAPI/JSON Schema), error handling, and pagination/streaming patterns. - Testing & Quality: Jest + React Testing Library, Cypress/Playwright, story-driven development (Storybook or similar), visual regression testing. - Security & Auth UX: OIDC/OAuth2 SSO flows, CSRF/XSS mitigations, secure handling of tokens/session state, and role-aware UI controls. - Performance: Profiling and optimization (bundle splitting, memoization, virtualization), Core Web Vitals awareness, and perceived-latency improvements. - Tooling: Git-based workflows, CI/CD familiarity, lint/format/type-safety discipline; strong documentation and design-handoff skills (Figma). Good to Have Skills - Explainability & Data Viz: Charts/tables and graph visualizations (e.g., Recharts, D3, Cytoscape.js/Sigma.js) for sources, subgraphs, and call graphs. - AI UX Patterns: Prompt/response UI nuances, citation rendering, safety/guardrail feedback messaging, and evaluation review panels. - Design Ops: Design token pipelines, theme packs, multi-brand support, and cross-repo component publishing (Storybook/Nx/Turborepo). - Observability: Frontend tracing/metrics (OpenTelemetry JS), UX analytics (Segment/GA4), and event taxonomy design. - Feature Delivery: LaunchDarkly/Flagsmith, canary/experimentation hooks, and remote config. This role is ideal for a hands-on developer who can turn complex reasoning and approval workflows into fast, accessible, and trustworthy experiences-while building the component foundations others can reuse. Compensation Estimated Pay Range: Exact compensation and offers of employment are dependent on circumstances of each case and will be determined based on job-related knowledge, skills, experience, licenses or certifications, and location. Our Commitment to Diversity & Inclusion At Milestone we strive to create a workplace that reflects the communities we serve and work with, where we all feel empowered to bring our full, authentic selves to work. We know creating a diverse and inclusive culture that champions equity and belonging is not only the right thing to do for ouremployees butis also critical to our continued success. Milestone Technologies provides equal employment opportunity for all applicants and employees. All qualified applicants will receive consideration for employment and will not be discriminated against on the basis of race, color, religion, gender, gender identity, marital status, age, disability, veteran status, sexual orientation, national origin, or any other category protected by applicable federal and state law, or local ordinance. Milestone also makes reasonable accommodations for disabled applicants and employees. We welcome the unique background, culture, experiences, knowledge, innovation, self-expression and perspectives you can bring to our global community. Our recruitment team is looking forward to meeting you.