React Developer - Sussex

Square One Resources; Burgess Hill; Hybrid; GBP 57,000 - 66,000; Full time

Job summary

Square One Resources is seeking an experienced React Developer to join a finance-focused software engineering team in West Sussex. You will design, develop, test and enhance responsive UIs using React and TypeScript, working in an Agile delivery environment on modern digital products for a leading global financial services organisation.

This hands-on role demands strong frontend engineering skills, experience with Redux/Context, RESTful APIs, and JSON-driven forms.

Qualifications

• Strong frontend experience with React and TS.
• Experience with Redux/Context API and RESTful APIs.
• Familiarity with automated testing and code quality standards.

Responsibilities

• Design and develop responsive UI with React and TS.
• Build dynamic, data-driven UIs and forms using JSON Schema.
• Implement state management with Redux/Context.
• Collaborate in Agile environment and contribute to reviews.

Skills

React

TypeScript

Frontend dev

JS ES6

HTML5

CSS3

React Hooks

Redux/Context

REST APIs

Testing Library

JSON Schema

Tools

React Testing Library

JSON Schema

Job description

React Developer - UI

Location:West Sussex
Office: 3 days per week mandatory
Contract: Initial12 months
Start Date: By mid-September 2026
Working Hours: 40 hours per week
Rate: £310-360 per day inside IR35

The Opportunity

We are looking for an experienced React Developer to join a high-performing software engineering team supporting a leading global financial services organisation. You?ll be working on modern, customer-focused digital products and data-driven web applications within a fast-paced, technology-led environment.

You will be responsible for designing, developing, testing and enhancing responsive user interfaces using React and TypeScript, while contributing to high standards of code quality, performance, security and maintainability.

This is a hands‑on role suited to someone with strong frontend engineering experience who enjoys working in an Agile product development environment and wants to contribute to innovative digital solutions within a globally recognised financial services business.

Key Responsibilities

• Design and develop modern, scalable web applications using React and TypeScript.
• Build dynamic, data-driven user interfaces and forms, including JSON Schema-based forms.
• Develop reusable React components using functional component patterns and React Hooks.
• Implement effective state management using Redux and/or Context API.
• Integrate frontend applications with RESTful APIs and web services.
• Develop and maintain high-quality application code aligned with industry standards and compliance requirements.
• Write and maintain automated tests using React Testing Library or similar frameworks.
• Participate in code reviews and contribute to engineering best practices.
• Identify and implement web application performance optimisation opportunities.
• Work closely with product, engineering and other stakeholders within an Agile delivery environment.
• Contribute to the mentoring and development of engineering team members where required.

Essential Skills & Experience

• Software engineering/product development experience.
• Strong commercial experience in UI / frontend development.
• Excellent hands‑on experience with React JS and TypeScript.
• Strong knowledge of JavaScript ES6 , HTML5 and CSS3.
• Experience with React Hooks and functional component architecture.
• Experience with Redux and/or Context API.
• Experience with React Testing Library or comparable frontend testing frameworks.
• Strong experience integrating applications with RESTful APIs.
• Hands‑on experience working with JSON and web service technologies.
• Experience developing data-driven UIs and dynamic forms.
• Understanding of frontend performance optimisation techniques.
• Experience working within Agile software development environments.
• Strong understanding of software engineering standards, code quality and maintainability.

Desirable Skills

• Node.js
• Java
• Experience mentoring or supporting other engineers.
• Experience working within distributed engineering teams.
• Professional certifications in software engineering, architecture, or product management.

What We’re Looking For

We're looking for a developer who is not only technically strong but also takes ownership of their work, contributes to engineering standards, and can collaborate effectively across a product-focused environment.

If you're a React and TypeScript specialist looking for a long-term contract opportunity, we'd be keen to hear from you.

Disclaimer

Notwithstanding any guidelines given to level of experience sought, we will consider candidates from outside this range if they can demonstrate the necessary competencies.