Senior GUI developer - Equities Technology

Citi; Mississauga; On-site; CAD 95,000 - 140,000; Full time

Job summary

Citi Equities Technology is seeking a Senior GUI Developer in Mississauga to join a collaborative team working with front office, product development and peers to build efficient, scalable web applications. The role requires 6–10 years of hands-on experience with React, Redux, TypeScript, and modern web tech.

You will design, develop, test, and maintain UI components, mentor others, and help shape frontend architecture and best practices.

Qualifications

• 6–10 years of experience in React, Redux, websockets and cutting-edge web technologies.
• Proficiency in HTML5, CSS/SASS and TypeScript.
• Experience with unit testing using Jest and React Testing Library.
• Experience with Redux, Recoil, or React context for state management.
• Familiarity with Webpack or Vite and modern build tools.
• Exposure to Electron for container-based development is a plus.
• Experience with RESTful APIs and Node.js/Express.
• Bachelor’s degree or equivalent experience.

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, implement functionality without direct supervision.
• Work closely with teams to form a good working culture and continuously adapt to different working environments.

Skills

HTML5

CSS/SASS

JavaScript

TypeScript

React

Redux

React Hooks

Jest

React Testing Library

Redux Toolkit

RxJS

Websockets

Web Workers

Webpack

Vite

Electron

REST APIs

NodeJS/Express

Education

Bachelor’s degree in CS or related

Tools

Bitbucket

Jenkins

Artifactory

Confluence

Docker

OpenShift

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, and 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, implement 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/CSS 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, web sockets, web workers.
• Build tools like Webpack, Vite, etc.
• Debugging skills, code performance, benchmarking.
• Container‑based development like Electron.
• RESTful APIs, JWT, NodeJS, 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 race, color, religion, sex, sexual orientation, gender identity, national origin, disability, status as a protected veteran, or any other characteristic protected by law.