Frontend Developer

Hallmark Global Solutions Ltd; Mississauga; On-site; CAD 110,000 - 190,000; Full time

Job summary

Hallmark Global Solutions Ltd is seeking a Lead Senior React Full Stack engineer to build AI-driven, micro-frontend web apps on a modern, event-driven platform. At least one hire should also be strong full-stack (Node/NestJS or Python backend).

You will work with data-heavy dashboards and real-time UI, emphasizing performance, accessibility, and robust testing. Banking/financial services experience is a plus; strong leadership and collaboration are expected.

Qualifications

• Extensive React and front-end experience with 10+ years overall.
• Strong full-stack capability (Node/NestJS or Python backend).
• Experience mentoring developers and leading teams.

Responsibilities

• Lead and mentor a team of developers on front-end and full-stack work.
• Build AI-driven, micro-frontend web apps on an event-driven platform.
• Collaborate with design, product, and backend teams for robust solutions.

Skills

React

Full-stack

Mentoring

Product-minded

Independent worker

Tools

Webpack 5

Module Federation

React Query

SWR

Vite

Next.js

Mantine

MUI

Testing Library

Jest

Cypress

Playwright

CI/CD

SSR/SSG

Job description

Lead Senior React Full Stack engineer to build AI-driven, micro-frontend web apps on a modern, event-driven platform. At least one hire should also be strong full-stack (Node/NestJS or Python backend).

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

• 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.

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.