Next JS Senior Engineer

This role is designed to strengthen our engineering capability in support of strategic digital transformation initiatives and business-critical web application projects. As a Senior Next.js Engineer, you will design and build modern, high-performance web applications using Next.js App Router, React Server Components (RSC), and Server Actions, delivering scalable solutions that support complex business workflows. Responsibilities • Design and build robust web applications using Next.js App Router, React Server Components (RSC), and Server Actions. • Develop and maintain scalable backend APIs to support complex business workflows. • Design and implement MongoDB data models and database schemas to support application requirements. • Build efficient server-side logic and integrations across the full application stack. • Apply clean code practices and SOLID design principles to deliver maintainable and extensible solutions. • Implement and optimise data-fetching strategies including SSR, SSG, and ISR. • Develop and maintain advanced caching mechanisms to improve application scalability and performance. • Optimise application assets and user experiences to achieve strong Core Web Vitals. • Implement end-to-end observability with New Relic, including logging, tracing, and metrics collection. • Monitor and troubleshoot application performance across both client-side and server-side (Node.js/Serverless) runtimes, driving continuous improvements in reliability and operational visibility. Required Skills • Next.js Expertise: Strong hands-on experience with Next.js App Router, React Server Components (RSC), and Server Actions for building modern web applications. • React & TypeScript Development: Proficiency in React, TypeScript, JavaScript (ES6+), component-based architecture, and modern frontend development practices. • Full-Stack Engineering: Experience developing scalable backend APIs, server-side logic, and end-to-end application functionality. • MongoDB & NoSQL Databases: Strong knowledge of MongoDB, data modelling, schema design, and database integration patterns. • Software Design Principles: Solid understanding of clean code practices, SOLID principles, and maintainable application architecture. • Performance Optimisation: Experience implementing SSR, SSG, ISR, caching strategies, and asset optimisation to achieve strong Core Web Vitals. • Observability & Monitoring: Hands-on experience with New Relic for application monitoring, distributed tracing, logging, and metrics collection. • Node.js Development: Experience developing and supporting server-side applications using Node.js runtimes. • Application Troubleshooting: Strong analytical and problem-solving skills with the ability to identify and resolve performance and application issues. • Agile Delivery: Experience working in Agile/Scrum environments, participating in sprint planning, reviews, retrospectives, and iterative software delivery. Preferred Skills • Retail Domain Experience: Knowledge of retail business processes and customer-facing digital platforms, preferably within large UK retail organisations. • Performance & Load Testing: Practical experience with performance, load, and scalability testing using tools such as k6, JMeter, or equivalent. • Microservices Architecture: Understanding of microservice architecture patterns, distributed systems, and service integration principles. • MongoDB Administration: Experience with MongoDB configuration, schema design, indexing strategies, and performance optimisation.