Full Stack Engineer

Job Title: Full-Stack Engineer Contract Type: B2B Contract Location: Remote About the Opportunity: The React Hub has partnered with a client operating a large-scale subscription-based social and creator platform. The client is currently rebuilding and modernising its core technology platform while expanding its engineering team. They are looking for a senior Full-Stack Engineer who can take ownership of complex systems across the frontend, backend, infrastructure, and overall architecture. Key Responsibilities: Own and evolve large-scale Next.js applications, currently using the Pages Router, with future migration toward App Router patterns.Manage complex frontend state using Redux and redux-saga.Improve frontend performance across high-traffic feeds and real-time user experiences.Design and develop robust backend services using NestJS, with strong validation, error handling, and API design principles.Build and maintain secure authentication and RBAC authorisation systems.Design and optimise relational and non-relational database schemas, queries, aggregations, and data-access patterns.Work with caching and queuing systems to support distributed and high-volume workloads.Understand and implement CDN and media-delivery concepts, including signed URLs, caching strategies, and content delivery.Collaborate with frontend, backend, DevOps, and platform engineers to establish engineering standards and improve system reliability.Contribute to architectural decisions and technical direction across the platform.Mentor engineers across the stack while continuing to deliver hands-on production code.Identify and resolve performance, scalability, and reliability challenges across the technology stack. Requirements: Strong senior-level production experience building and operating full-stack web applications.Excellent experience with React and Next.js or comparable modern frontend frameworks.Strong understanding of frontend state management, ideally with Redux and redux-saga.Proven experience designing and developing robust backend APIs and services.Experience with authentication, authorisation, RBAC, and application security.Strong knowledge of both relational and non-relational databases.Experience with caching, queues, and distributed systems.Hands-on experience with Docker, Kubernetes, and cloud-native environments.Understanding of GitOps and modern software delivery workflows.Strong production experience with TypeScript and a typed backend language such as .NETAbility to work across the stack and take ownership of technical problems from design through to production.