Lead Full-Stack Developer: Next.js/Node.js E-commerce

Job Title: Lead Full-Stack Developer ([login to view URL] / Node.js) – E-commerce WMS & Shopify Integration Job Description: We are an e-commerce brand looking for an expert Full-Stack Developer ([login to view URL] + Node.js/TypeScript) to take over the ongoing maintenance, security, and continuous development of our custom-built Warehouse Management System (WMS). You will not be building this from scratch. The system is already live and fully operational. We own the GitHub repository and infrastructure, and we need a reliable, long-term technical partner to manage the codebase, fix bugs, build new features, and maintain clear documentation. Our Tech Stack: Frontend: [login to view URL] (React) Backend: Node.js with TypeScript Database: PostgreSQ Hosting/Infrastructure: Serverless / PaaS cloud environment Key Integrations: Shopify GraphQL API, 3rd-Party Courier/Logistics APIs, Transactional Email/SMS APIs, and Meta/WhatsApp Developer APIs. Your Responsibilities: Codebase Takeover & Audit: Review the existing repository, set up your local environment, and identify any technical debt. Security & Access Audit: Review backend authorisation logic to ensure strict security protocols. Ongoing Maintenance & New Development: Monitor system stability, resolve daily bug reports from the warehouse team, and build new features and UI enhancements as our operations scale. Performance Optimisation: Ensure high-volume PDF shipping label generation and high-frequency background cron jobs (do not cause memory leaks or server timeouts. Technical Documentation: Create, update, and actively maintain comprehensive documentation for the system architecture, API workflows, and codebase changes so our internal engineering team remains aligned. Required Experience: Deep expertise in Node.js, TypeScript, and Next.js. Proven experience working with the Shopify GraphQL API (REST experience is not enough). Experience building or maintaining WMS, ERP, or heavy inventory logistics applications. Solid understanding of PostgreSQL and relational database optimization. Strong habit of writing clean code and detailed technical documentation. Engagement Model: We are looking for a long-term, ongoing relationship (Monthly Retainer or Weekly Hourly limit). Please state your required monthly or hourly rate in your proposal.

Project ID: 40479263