React Developer

Rullion; Greater London; On-site; GBP 130,000 - 170,000; Full time

Job summary

We are seeking a Senior Frontend Developer to join a high-performing engineering team in the UK. You will own frontend feature delivery from design through production, building and maintaining React and Next.js applications while collaborating with Designers, Backend, Product and Platform teams.

You will contribute to modernising frontend platforms, delivering scalable and well-tested solutions, and mentoring junior developers within agile squads.

Qualifications

• Senior-level frontend engineering experience.
• Experience with React and Next.js.
• Experience in large-scale frontend applications.

Responsibilities

• Own frontend feature delivery from design to production.
• Build and maintain React and Next.js applications.
• Develop clean, scalable TypeScript code and test coverage.

Skills

Senior frontend engineer

Mentoring

Agile teamwork

Stakeholder communication

Tools

React

Next.js

Tailwind CSS

Playwright

Jest

Vitest

Git-based CI/CD

Job description

We are looking for a talented Senior Frontend Developer to join a high-performing engineering team working on business-critical customer and colleague applications. This is an opportunity to contribute to modern web applications, deliver impactful features, and help drive the evolution of frontend platforms in a collaborative and fast-paced environment.

You'll work closely with designers, backend engineers, product teams, and platform specialists to build scalable, maintainable, and high-quality solutions using modern frontend technologies.

• Role: Senior Frontend Developer
• Contract Type: Inside IR35
• Start Date: ASAP (flexible for the right candidate)
• Duration: 6 Months possibility to extend
• Rate: Up to £650 per day
• Hours: 40 hours per week

The Role

You will primarily work on an established telephony platform used by customer-facing teams to manage inbound and outbound communications. The role involves delivering new features, supporting existing functionality, and helping modernise frontend systems as part of ongoing platform transformation projects.

Responsibilities include:

• Taking ownership of frontend feature delivery from design through to production
• Building and maintaining React and Next.js applications
• Developing clean, scalable, and well-tested TypeScript code
• Supporting the migration and modernisation of existing frontend platforms
• Working with shared component libraries and design systems
• Debugging production issues and improving application performance
• Contributing to CI/CD processes and deployment pipelines
• Participating in code reviews and mentoring less experienced developers
• Collaborating with Product, Design, Backend and Platform teams
• Making pragmatic technical decisions that balance delivery, quality, and maintainability
• React
• TypeScript
• Tailwind CSS
• Playwright
• Jest
• Vitest
• Git-based CI/CD pipelines
• Monitoring and observability tools
• Cloud-based infrastructure environments
• Strong commercial experience with React
• Proven expertise with Next.js
• Senior-level frontend engineering experience
• Experience working within large-scale frontend applications
• Strong testing background using tools such as Playwright, Jest, and Vitest
• Ability to work independently while collaborating effectively within agile squads
• Experience troubleshooting and resolving production issues
• Excellent communication and stakeholder management skills
• Experience with telephony or contact-centre applications
• Knowledge of Twilio integrations
• Experience working with design systems and component libraries
• Exposure to cloud-native environments and modern DevOps practices
• Previous experience mentoring developers and supporting technical growth within teams

What We're Looking For

We're seeking a senior engineer who enjoys solving complex frontend challenges, delivering high-quality customer-focused solutions, and working within a collaborative engineering culture. You'll be comfortable owning features end-to-end, contributing to technical discussions, and helping shape the future direction of modern web applications.

This role would suit someone who combines strong technical expertise with a practical, delivery-focused mindset and a passion for building exceptional user experiences.