Principal Front End Engineer

About Us:

Solirius Reply , part of the Reply Group , is a technology consultancy and digital transformation partner that helps organisations solve complex challenges through strategy, design, engineering, and delivery.

We work closely with our clients to deliver secure, accessible, user-focused services that evolve with their needs. By combining deep technical expertise with people-centred design, we create solutions that deliver meaningful, lasting impact.

Our consultants partner directly with client teams, embedding into organisations to understand their goals, challenges, and users. This collaborative approach enables us to deliver tailored solutions that drive measurable outcomes across public and private sectors.

Past and present clients include the Ministry of Justice, Department for Education, Ministry of Housing, Communities and Local Government, UEFA, International Olympic Committee, and Mercedes-Benz. Our services span the full digital delivery lifecycle, including architecture, engineering, delivery management, user-centred design, business analysis, data, DevOps, and AI.

We operate as a collaborative and inclusive organisation that empowers our people to take ownership, innovate, and develop their expertise. As an equal opportunities employer, we are committed to encouraging equality, diversity, and social mobility, while creating opportunities for our teams to work on meaningful projects that deliver lasting impact.

About You:

You are a motivated and adaptable professional with a strong analytical mindset and a passion for using technology to solve real-world problems. You enjoy working in collaborative, agile teams and take pride in delivering high-quality solutions that make a tangible impact. With strong communication skills and a consultative approach, you’re comfortable engaging with clients, understanding their needs, and translating them into effective outcomes.

The Role:

We are seeking a highly experienced Principal Front End Engineer to lead the architecture, development, and evolution of our web applications and user experiences. This role combines hands-on technical leadership with strategic influence across engineering, product, and design teams.

As a Principal Engineer, you will define front-end standards, mentor engineers, drive platform scalability, and ensure exceptional performance, accessibility, and usability across our products.

Requirements

Key Responsibilities:

• Lead the design and implementation of scalable, maintainable front-end architectures
• Drive technical strategy and establish engineering best practices for UI development
• Build high-performance, responsive, and accessible web applications
• Collaborate closely with Product, Design, and Back-End Engineering teams to deliver exceptional user experiences
• Own and evolve shared component libraries, design systems, and front-end tooling
• Improve application performance, reliability, observability, and developer experience
• Mentor senior and mid-level engineers through technical guidance, code reviews, and architectural leadership
• Evaluate and introduce modern front-end technologies and frameworks where appropriate
• Influence roadmap planning and technical decision-making across multiple teams
• Champion testing strategies including unit, integration, visual regression, and end-to-end testing
• Ensure adherence to accessibility, security, and compliance standards
• Lead incident response and root cause analysis for front-end production issues

Key Skills/Experience:

• Software engineering experience with significant focus on front-end development
• Deep expertise in JavaScript, TypeScript, HTML5, and CSS3
• Extensive experience with modern frameworks such as React, Next.js, Vue, or Angular
• Strong understanding of front-end architecture patterns, state management, and component-driven development
• Experience building and scaling design systems and reusable UI platforms
• Strong knowledge of web performance optimisation techniques
• Expertise in accessibility standards (WCAG) and responsive design
• Experience with testing frameworks such as Jest, Cypress, Playwright, or Vitest
• Strong understanding of CI/CD pipelines and modern development workflows
• Proven track record of leading large-scale technical initiatives
• Excellent communication and stakeholder management skills

Preferred Qualifications:

• Experience with micro-frontends or distributed front-end architectures
• Familiarity with cloud platforms such as AWS, Azure, or GCP
• Experience with GraphQL and modern API integration patterns
• Knowledge of observability and monitoring tools
• Experience leading globally distributed engineering teams
• Contributions to open-source projects or technical communities

Benefits

• Competitive Salary
• Bonus Scheme
• Private Healthcare Insurance
• 25 Days Annual Leave + Bank Holidays
• Up to 10 days allocated for development training per year
• Enhanced Parental Leave
• Paid Fertility Leave (5 Days)
• Statutory & Contributory Pension
• EAP with Help@Hand
• Gym Membership Benefits
• Cycle to Work and Electric Vehicle schemes
• Flexible Working
• Annual Away Days/Company Socials

Diversity and Inclusion

As an equal opportunities employer, we are committed to creating a work environment that supports, celebrates, encourages and respects all individuals, where all processes are based on merit, competence and business needs.

Encouraging high social mobility is really important to us. We foster an inclusive culture by welcoming different perspectives, enabling equitable opportunities and promoting open dialogue. This commitment is reflected in initiatives such as our gender diversity group and our focus on mental health and wellbeing. Whatever stage you are at, you will find an environment where you can thrive.

Should you require further assistance or require any reasonable adjustments to be put in place to better support your application process, please do not hesitate to raise this with us.

As a Disability Confident employer, we are committed to ensuring our recruitment process is accessible and inclusive, enabling all candidates to demonstrate their skills, experience and potential.