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Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md). --- # NodeJS Developer - **Company:** Ai-assisted - **Location:** Madrid, Spain (Remote available) - **Contract:** Permanent contract - **Skills:** Clean Code Principles, JavaScript (Programming Language), Abstraction Layers, Artificial Intelligence, Unit Testing, Communications Protocols, Databases, Dependency Injection, DevOps, Hypertext Transfer Protocols (HTTP), Web Servers, Network Troubleshooting, Modular Design, Network Forensics, Network Service, Node.Js, Performance Tuning, Software Architecture, Role-Based Access Control, E2e Testing, Prometheus, Reverse Engineering, Software Engineering, SQL Databases, TypeScript, Web Applications, WebSocket, Openapi, Data Logging, Load Balancing, ReactJS, Browserstack, Caching, Backend, Data Layers, Database Migration, Webpack, Gitlab-ci, Integration Tests, Kubernetes, Playwright, Integration Frameworks, Browser Testing, Front End Software Development, Asynchronous Programming, Restful APIs, Workday, Docker, Monolithic Repository - **Published:** July 20, 2026 - **Apply:** https://www.adzuna.es/contact-us.html ## About the Role + 5+ years of commercial experience with TypeScript and JavaScript. + Strong expertise in Node.js development. + Deep understanding of: + Asynchronous programming + Event loops + Streams + Error handling + High-performance backend systems Experience designing and maintaining production-grade services.Networking Knowledge + Practical understanding of: + HTTP/1.1 and HTTP/2 + WebSocket + TLS + HTTP headers + Caching + Compression Ability to troubleshoot real-world networking problems.Software Architecture + Experience designing modular systems with: + Clean boundaries + Dependency Injection + Type-safe contracts + Maintainable code structures Strong understanding of scalable application architecture.Testing & Quality + Experience with: + Unit testing + Integration testing + End-to-end testing Comfortable using TDD as a practical engineering tool.Databases + Strong knowledge of SQL databases. + Experience with ORM frameworks and database migrations. + Understanding of indexes, transactions, and performance optimization. DevOps & Observability + Experience with monitoring, logging, and tracing. + Familiarity with CI/CD pipelines and monorepo workflows. + Understanding of production environments and performance under load. Highly Valued ExperienceReverse Engineering & Web Client Analysis We highly value engineers who have experience working with third-party web applications and browser internals, including: + Reading and understanding minified or obfuscated JavaScript bundles. + Reverse engineering application behavior without source code. + Network traffic analysis using HAR files and proxy tools. ## Description Inscribirse en esta oferta About the Role We are looking for a Senior Node.js Developer to join our team and help build a distributed, high-load real-time networking platform that processes, transforms, and routes large volumes of HTTP and WebSocket traffic between clients and external services. This is a highly technical engineering role focused on network services, protocol-level development, observability, runtime integrations, and modern software architecture. Our platform is built as a large TypeScript monorepository running simultaneously on both Node.js and Bun, with a unified abstraction layer. We actively embrace AI-assisted development practices and expect engineers to take ownership throughout the entire software lifecycle-from research and design to implementation, testing, deployment, and continuous improvement. What You'll DoCore Platform Development + Design, develop, and optimize services within our networking core. + Build highly reliable systems for request processing, routing, load balancing, failover, and streaming data delivery. + Contribute to platform scalability, performance, and operational excellence. Network Protocol Engineering + Work directly with: + HTTP/1.1 + HTTP/2 + WebSocket + TLS + CONNECT tunneling + Compression technologies (gzip, brotli, zstd, deflate) Diagnose and resolve complex networking issues in production environments.Observability & Reliability + Implement tracing, metrics, and logging using OpenTelemetry. + Build dashboards and alerts generated directly from code. + Analyze system behavior under load and improve operational visibility. Third-Party Integrations + Maintain and extend runtime integrations with external web applications. + Develop compatibility layers between internal systems and third-party clients. Software Engineering Excellence + Write portable TypeScript code compatible with both Node.js and Bun runtimes. + Ensure proper tree-shaking, modular design, and absence of cyclic dependencies. + Participate in architecture discussions and technical decision-making. Full Ownership Delivery + Own projects end-to-end: + Research + Design + Planning + Development + QA + Documentation + Retrospectives Leverage AI tools as an integral part of the engineering workflow., + Cross-browser testing using Playwright and BrowserStack. AI-Assisted Development We actively build our engineering processes around AI-assisted development practices. We are looking for engineers who: + Use AI critically and responsibly. + Verify generated code and recommendations. + Follow structured workflows from research to implementation. + Understand security considerations when working with AI tools. + Take ownership of outcomes rather than relying blindly on generated solutions. Tech StackCore + TypeScript (strict mode) + Node.js + Bun Monorepo & Tooling + pnpm Workspaces + Turborepo + BiomeJS Networking + HTTP/1.1 + HTTP/2 + WebSocket + TLS + Circuit Breakers + Load Balancing Backend + REST APIs + OpenAPI + RFC 9457 Problem Details Data Layer + SQL + Drizzle ORM + Database Migrations + Hexagonal Architecture Observability + OpenTelemetry + Prometheus + Grafana + SigNoz + VictoriaMetrics Infrastructure + Docker + Kubernetes + Helm + GitLab CI Frontend (Admin Panel) + React 19+ + Ant Design + Vite + TanStack Query Security + AES-256-GCM + HKDF + HMAC Signatures + JWT / RBAC + SSRF Protection + Rate Limiting Testing + Vitest + Bun Test + Playwright Benefits + 20 vacation days and 5 family days yearly + Flexible start to the workday + Support from a professional corporate coach and psychologist + Regular internal and external activities, workshops, trips, and corporate events + Access to our internal knowledge base, meetups, and team-building activities + Ongoing training in new technologies and continuous professional development support Inscribirse en esta oferta ## Related Videos - [Stop using Node.js like in 2020! 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