Senior React Developer Full Time/ Permanent Location: Downtown Toronto, ON (4 days/week Onsite) About the Role Were looking for a Senior React Developer who goes beyond writing codeyou build exceptional user experiences.

In this role, youll help shape the architecture, performance, and direction of modern front-end applications used at scale.

Youll collaborate closely with product designers and back-end engineers to bring complex interfaces to life, establish front-end best practices, and mentor other developers.

What Youll Do Design and develop scalable React applications using contemporary patterns and best practices Define and drive front-end architecture and technical standards Translate complex UI/UX designs into high-quality, production-ready code Optimize applications for performance, responsiveness, and accessibility Mentor and support junior and mid-level developers Collaborate cross-functionally to deliver high-quality features What You Bring Front-End Expertise Deep experience with Java





Script and contemporary front-end development Strong proficiency in React and its ecosystem Solid understanding of component architecture and composition Architectural Thinking Ability to design scalable, maintainable front-end systems Strong grasp of performance techniques (e.g., memoization, lazy loading) Understanding of React internals, including rendering and reconciliation Attention to Detail High standards for UI quality, consistency, and accessibility Ability to accurately translate design files into polished interfaces State Management Experience Experience with state management libraries such as Redux, MobX, Zustand, or Context API Familiarity with Jotai is a plus (or willingness to learn quickly) Performance Mindset Experience profiling and optimizing front-end performance Understanding of code-splitting, caching strategies, and load optimization Awareness of both perceived and actual performance considerations Tech Stack React (Hooks, Context, Suspense) Type

Script (preferred) State management (Jotai preferred) Build tools (Vite, Webpack, ESBuild) Testing (Jest, React Testing Library) Contemporary CSS solutions (CSS-in-JS or frameworks) Git and CI/CD pipelines

📌 Senior React Developer To Collaborate Closely With Product Designers And Back End Engineers To Bring Complex Interfaces To Life, Establish Front End Best Practices, And Mentor Other Developers For Our Financial Services Client Toronto
🏢 S.i. Systems
📍 Toronto