Onsite Full-Stack JS Developer (React/Node) in Essex

Devonshire Hayes Recruitment Specialists Limited; Essex; On-site; GBP 45,000 - 65,000; Full time

Job summary

Devonshire Hayes Recruitment Specialists Limited is recruiting a Mid-Level Full-Stack JavaScript Developer to build customer-journey screens in React and backend services in Node.js. The role requires onsite attendance four days a week in Upminster, Essex, and involves delivering REST APIs, database migrations, and integrating third-party services.

You will work across a React frontend, a Node.js backend with Fastify/Express, and SQL Server, writing tests and ensuring robust, compliant software

Qualifications

• Three years of professional JavaScript development across front-end and back-end
• Strong React fundamentals: hooks, routing, state management
• Experience building and consuming REST APIs in Node.js (Fastify/Express)
• Practical SQL knowledge; SQL Server helpful
• Genuine testing habit and ability to document decisions
• Clear written communication and ability to document trade-offs

Responsibilities

• Build and maintain customer-journey screens and components in React using Router, Vite and SCSS across multiple branded sites
• Develop back-end features in Node.js, including Fastify API, backend-for-frontend and SQL-backed outbox queue
• Design and evolve SQL Server schema through forward-only migrations with parameterised queries
• Integrate third-party services (identity-verification, lead-management) behind clean interfaces
• Write tests across layers: Vitest, Testing Library, Playwright with a real database in Docker
• Ensure regulated product requirements: input validation, PII handling, audit trails, idempotent retries
• Document technical decisions and collaborate to improve the platform

Skills

JavaScript

React

Node.js

REST APIs

Testing

ESM tooling

UI state management

Tools

Fastify

Express

Vitest

Playwright

Docker

SQL Server

Job description

Devonshire Hayes Recruitment Specialists Limited is recruiting a Mid-Level Full-Stack JavaScript Developer to build customer-journey screens in React and backend services in Node.js. The role requires onsite attendance four days a week in Upminster, Essex, and involves delivering REST APIs, database migrations, and integrating third-party services.

You will work across a React frontend, a Node.js backend with Fastify/Express, and SQL Server, writing tests and ensuring robust, compliant software