Mid-Level Full Stack JavaScript Developer

Full-Stack JavaScript Developer React, Node.js and SQL Server | Multi-brand claims technology Company P&J Moore Ltd Location Upminster, Essex, UK Working pattern On Site Salary £40,000-£60,000, depending on experience Employment type Full-time The opportunity We're building a multi-brand claims-acquisition platform that guides consumers through the complete online claims journey, from their first visit through identity verification, e-signature and submission. As a Mid-Level Full-Stack JavaScript Developer, you'll work across the platform: a React single-page application on the front end, Node.js APIs and background workers on the back end, and Microsoft SQL Server as the system of record. This is a hands-on product engineering role where you'll ship customer-facing journey steps, build and consume REST APIs, write database migrations and integrate third-party services behind clean, maintainable interfaces. What you'll do • Build and maintain customer-journey screens and shared components in React 19, using React Router 7, Vite and Sass/SCSS across multiple branded sites from a single codebase. • Develop back-end features in Node.js, including a Fastify API, an Express backend-for-frontend and durable background jobs processed through a SQL-backed outbox queue. • Design and evolve the SQL Server schema through forward-only migrations, using parameterised queries and transactional business logic. • Integrate and mock third-party services, including identity-verification and lead-management providers, while keeping transport details behind well-defined interfaces. • Write meaningful tests at every layer: Vitest unit and route tests, Testing Library component tests, and Playwright end-to-end journeys against a real database running in Docker. • Build with the needs of a regulated consumer product in mind, including robust input validation, careful PII handling, audit trails, idempotent retries and graceful degradation. • Work collaboratively to document technical decisions, follow established conventions and improve the platform as it grows. What you'll bring • At least three years of professional JavaScript development experience, with meaningful hands-on work across both front-end and back-end development. • Strong React fundamentals, including hooks, controlled forms, routing and state management, together with confidence using modern ESM tooling. • Experience building and consuming REST APIs in Node.js using Fastify, Express or a comparable framework. • Practical SQL knowledge covering schema design, joins, transactions and indexes. SQL Server experience is helpful but not essential. • A genuine testing habit: you write useful tests because they prevent defects and support confident delivery, not simply because the CI pipeline requires them. • Clear written communication and the ability to document decisions, explain trade-offs and work within established conventions. Nice to have • Experience working on multi-tenant or multi-brand products. • Familiarity with queue or outbox patterns, Redis, PM2, nginx or Cloudflare. • Exposure to regulated industries such as claims, finance or insurance, or experience with KYC and identity-verification journeys. Our technology stack React 19 | React Router 7 | Vite | Sass/SCSS | Express BFF | Fastify 5 | Node.js 20 | Microsoft SQL Server | Redis | Vitest | Playwright | Docker | Bitbucket Pipelines