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 up-to-date, 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

📌 Lead Senior React Full Stack Engineer (Mississauga)
🏢 Extend Information Systems
📍 Mississauga