Senior Backend Engineer

We're working with a major UK organisation building a next-generation knowledge platform that combines structured data, graph technology, and AI-enabled workflows. This is a senior front-end role focused on developing high-performance interfaces that interact directly with a semantic knowledge graph platform.   Key Responsibilities Build and maintain complex React/Next.js applications in a modern TypeScript codebase Develop rich UI experiences powered by GraphQL APIs connected to Amazon Neptune Create advanced Search & Discovery interfaces, combining keyword and AI/vector-based retrieval Build dashboards supporting human-in-the-loop validation of AI-generated outputs Ensure strict adherence to WCAG 2.2 AA accessibility and design system standards Collaborate closely with backend engineers, data teams, and UX/service designers Integrate front-end applications with AWS-hosted services (Lambda, API Gateway, ECS)   Core Skills Required Strong front-end engineering experience with React or Next.js + TypeScript Proven expertise consuming and delivering applications built on GraphQL APIs Hands-on experience working with GraphQL backed by Amazon Neptune is essential Strong state management skills (Redux, TanStack Query, or similar) Deep practical accessibility experience (WCAG standards) UK-based and able to meet security and governance requirements   Desirable Experience Knowledge graph or semantic data awareness (RDF, JSON-LD, linked data concepts) Experience building high-performance search UIs (OpenSearch, Elastic, vector search) Familiarity with CI/CD pipelines and Infrastructure-as-Code (Terraform/CDK) Interest in AI-enabled workflows and validation tooling   Please note: GraphQL experience specifically with Amazon Neptune is an absolute minimum requirement. Applications without this will not be considered.