Full-Stack TypeScript Developer for Digital Top-Up Platform — NestJS & React

We are looking for an experienced full-stack developer to build and maintain a production-ready B2B digital top-up platform. The platform consists of a secure REST API used by client accounts and a responsive administration dashboard for managing users, wallets, and mobile top-up transactions. The developer should be comfortable owning backend architecture, frontend integration, testing, and deployment. Key responsibilities include: - Develop a modular NestJS and TypeScript backend using vertical-slice and CQRS patterns. - Implement JWT authentication, refresh tokens, role-based authorization, API-key authentication, and rate limiting. - Build client-account and user-management functionality. - Implement wallets with available and reserved balances, deposits, transaction reservations, and an auditable ledger. - Manage digital products and configurable top-up offers. - Build the mobile top-up workflow, including amount and phone-number validation, external transaction IDs, duplicate prevention, balance checks, and status lookup. - Implement reliable asynchronous provider processing using Redis, BullMQ, retries, recovery jobs, and the transactional outbox pattern. - Provide consistent API error responses, Swagger documentation, pagination, filtering, and sorting. - Develop a responsive React administration dashboard for authentication, user and wallet visibility, and transaction monitoring. - Add transaction and user search, filters, pagination, status indicators, and copy-to-clipboard utilities. - Write unit, integration, and browser-based tests. - Configure PostgreSQL migrations, Docker images, CI pipelines, health checks, CORS, and structured logging. - Deploy the API and dashboard to an Ubuntu VPS using Docker and Dokploy, with Ansible-based provisioning and production observability. The frontend technology stack includes React, TypeScript, Vite, TanStack Router, TanStack Query, Tailwind CSS, shadcn/ui, Zustand, Axios, Zod, Vitest, and Playwright. The backend technology stack includes NestJS, TypeScript, PostgreSQL, TypeORM, Redis, BullMQ, JWT, Swagger/OpenAPI, Jest, Docker, GitHub Actions, Ansible, Dokploy, Pino, and Grafana/Loki. Expected deliverables: - Production-ready backend API and administration dashboard. - Database schema and migrations. - Secure authentication and authorization. - Reliable wallet and top-up transaction processing. - Automated tests and CI checks. - API documentation and example HTTP requests. - Dockerized deployment with environment and operations documentation. - Clean, maintainable source code suitable for future integrations and ongoing development. The ideal candidate has strong experience with transactional systems, REST API design, PostgreSQL consistency, asynchronous job processing, React administration interfaces, and end-to-end production deployment. Experience with fintech, payment, telecom, wallet, or digital-product platforms is highly desirable. This may begin as a defined project and continue into ongoing maintenance, provider integrations, dashboard enhancements, and operational support. ---------------------------------------- Suggested Upwork skills: TypeScript, NestJS, Node.js, React, PostgreSQL, Redis, REST API, Docker, TypeORM, Tailwind CSS, DevOps, and Full-Stack Development.