Senior GUI developer - Equities Technology

Citigroup Inc.; Mississauga; On-site; CAD 110,000 - 160,000; Full time

Job summary

Citigroup Inc. in Mississauga is seeking a Senior GUI Developer to collaborate with front office, product development and engineering to deliver efficient, scalable web applications.

The role requires 6–10 years of experience with React, Redux, websockets and modern web technologies, plus strong communication and stakeholder management skills.

Qualifications

• Hands on HTML5, CSS3/SASS/JS-in-JS, Core JavaScript, TypeScript.
• Hands on React, React hooks.
• Unit Testing with Jest, React Testing Library.
• Application State Management with Redux, Recoil, React Context.
• Reactive Apps with RxJS, WebSockets, Web Workers.
• Build Tools like Webpack/Vite, etc.
• Debugging skills, code performance, benchmarking.
• Container‑based development like Electron.
• RESTful APIs, JWT, Node.js, Express.js.

Responsibilities

• Design, develop and maintain web apps using React and TypeScript, ensuring high quality, clean and maintainable code.
• Manage application state using Redux and middleware such as Redux Toolkit.
• Ensure high test coverage by writing unit tests using Vitest.
• Write and maintain a suite of reusable UI components that can be used across different feature apps.
• Contribute to the overall application architecture and provide inputs on front‑end frameworks, design patterns and best practices.
• Perform code reviews and contribute to overall quality, maintainability and testability of software developed.
• Be a self‑starter and plan/schedule own work for tasks and projects, implementing functionality without direct supervision.
• Work closely with teams to form a good working culture and continuously adapt to different working environments.

Skills

React

TypeScript

Redux

WebSockets

HTML5

CSS/SASS

Unit Testing

JavaScript

Education

Bachelor’s degree

Tools

Jest

React Testing Library

Redux Toolkit

Webpack

Vite

Electron

Docker

Job description

This role is for a Senior GUI developer in Citi Equities Technology. As a senior developer, you will work together with front office, product development and members of the development team to provide solutions that improve efficiency, decrease operational risk, and enable the business to expand.

The candidate should possess strong analytical and technical ability with 6-10 years of experience in React, Redux, websockets and cutting‑edge web technologies. The candidate should be able to work independently as well as being a team player, with good communication skills and stakeholder management.

Responsibilities

• Design, develop and maintain web apps using React and TypeScript, ensuring high quality, clean and maintainable code.
• Manage application state using Redux and middleware such as Redux Toolkit.
• Ensure high test coverage by writing unit tests using Vitest.
• Write and maintain a suite of reusable UI components that can be used across different feature apps.
• Contribute to the overall application architecture and provide inputs on front‑end frameworks, design patterns and best practices.
• Perform code reviews and contribute to overall quality, maintainability and testability of software developed.
• Be a self‑starter and plan/schedule own work for tasks and projects, implementing functionality without direct supervision.
• Work closely with teams to form a good working culture and continuously adapt to different working environments.

Requirements

• Hands on HTML5, CSS3/SASS/JS-in-JS, Core JavaScript, TypeScript
• Hands on React, React hooks
• Unit Testing with Jest, React Testing Library
• Application State Management with Redux, Recoil, React Context
• Reactive Apps with RxJS, WebSockets, Web Workers
• Build Tools like Webpack/Vite, etc.
• Debugging skills, code performance, benchmarking
• Container‑based development like Electron
• RESTful APIs, JWT, Node.js, Express.js

Nice to have

• Exposure to Bitbucket, Jenkins, Artifactory, Confluence
• MongoDB, AMPS Server – should be able to query
• Workspace tools – npm workspace, Micro Frontend, ESLint/TSLint
• Docker management, OpenShift containers
• Experience working with other UI frameworks such as Angular

Education

• Bachelor’s degree/University degree or equivalent experience

This job description provides a high‑level review of the types of work performed. Other job‑related duties may be assigned as required.

Citi is an equal opportunity employer, and qualified candidates will receive consideration without regard to their race, color, religion, sex, sexual orientation, gender identity, national origin, disability, status as a protected veteran, or any other characteristic protected by law.

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