Senior Full Stack Mobile Dev — React Native (Onsite, Toronto)

S.I. Systems Ltd.; Toronto; On-site; CAD 110,000 - 160,000; Full time

Job summary

S.I. Systems Ltd. in Downtown Toronto is seeking a Senior Full Stack / React Native Developer to support a major aviation client project.

You will own features end-to-end across mobile and backend, using React Native, Expo, Node.js, and GraphQL. The role requires strong frontend expertise, cloud/serverless experience, DevOps skills, and the ability to work autonomously. Expected duration is 1 year with on-site work four days a week.

Qualifications

• Senior, hands-on developer with ownership of features.
• Experience delivering iOS and Android apps with React Native.
• Backend and cloud/serverless development experience.
• Experience with AI-assisted development tools (Cursor/Claude Code).
• Strong collaboration with cross-functional teams.

Responsibilities

• Design, develop, test, and deploy mobile apps for iOS and Android using React Native and Expo.
• Take end-to-end ownership of features from requirements to production support.
• Develop scalable frontend solutions with React Native, Expo, React, and TypeScript.
• Build and integrate backend services using Node.js, GraphQL, and cloud/serverless tech.
• Develop and consume GraphQL APIs with Apollo Client and GraphQL Codegen.
• Manage application state with Jotai and cache persistence.

Skills

React Native

Expo

React

TypeScript

GraphQL

Apollo Client

AWS serverless

CI/CD

AI tools (Cursor/Claude Code)

Node.js

iOS/Android

Tools

GraphQL Codegen

Firebase

CI/CD pipelines

Job description

S.I. Systems Ltd. in Downtown Toronto is seeking a Senior Full Stack / React Native Developer to support a major aviation client project.

You will own features end-to-end across mobile and backend, using React Native, Expo, Node.js, and GraphQL. The role requires strong frontend expertise, cloud/serverless experience, DevOps skills, and the ability to work autonomously. Expected duration is 1 year with on-site work four days a week.