Senior Frontend developer

Project overview

Senior Frontend Developer (Contract)

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.

Contract Details

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.

• Role: Senior Frontend Developer
• Contract Type: Inside IR35
• Start Date: ASAP (flexible for the right candidate)
• Duration: Until the end of 2026 with potential extension
• Rate: Up to £650 per day
• Working Pattern: Hybrid
• 1 day per week on-site in London (Thursdays)
• Hours: 40 hours per week

Responsibilities

Technology Stack

Essential Skills & Experience

Desirable Experience

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.

Rullion celebrates and supports diversity and is committed to ensuring equal opportunities for both employees and applicants.

• 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
• Next.js (App Router)
• TypeScript
• Tailwind CSS
• Component Design Systems
• 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
• Advanced TypeScript development experience
• 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

Project details

• Start: flexible
• Location: City of London, London, GB
• Rate: 81-88 EUR/h