Lead Senior React Full Stack Engineer

Lead Senior React Full Stack Engineer Mississauga ON Canada – Onsite JD Lead Senior React Full Stack engineer to build AI-driven, micro-frontend web apps on a modern, event-driven platform. The Profile • 10+ years front-end / full-stack; 8+ years hands-on React. • Works independently with light direction; product-minded; banking / financial services a plus. • 5+ years leading and mentoring developers. Must-Haves • React 18 (hooks, modern patterns) + strong TypeScript (ES2020+, generics). • Webpack 5 Module Federation / micro-frontends — wiring host shells and remote MFEs. (Vite / Next.js / other modern build setups count too.) • State management (valtio / Zustand / Redux / Recoil) and react-router 6. • API & data fetching — REST (or GraphQL), and server-state libraries (React Query / SWR), with proper loading / error / cancellation handling. • Design systems (Mantine / MUI / Ant Design or similar) and HTML, CSS, SCSS/Sass; responsive, accessible UI (WCAG / ARIA). • Real-time UI via Server-Sent Events (SSE) / WebSockets (e.g., LLM token streaming). • Data-heavy dashboards — building performant, data-dense UIs (tables, grids, charts) that handle large datasets smoothly. • Testing: Jest + React Testing Library and E2E (Cypress / Playwright). • Git workflow (branching, PRs, code review), CI/CD, and performance / bundle optimization (code splitting, lazy loading, virtualization). • Familiarity with SSR / SSG (Next.js or similar) is a plus. Full-Stack • Node.js + NestJS (or Python) building REST APIs / backend-for-frontend. • MongoDB / Mongoose, Postgres, Kafka (KafkaJS), JWT auth, OpenAPI / Swagger. Strong Plus — AI Interface Skills Priority: building chat / assistant UIs that stream responses token-by-token, code safely (XSS-safe), and visualize agentic tool-use workflows. Bonus: LLM / GenAI API integration (RAG, embeddings), accessibility (WCAG), and telemetry. Nice to Have • Has previously worked in startup • Ability to wearing multiple hats in team