Senior Full Stack Engineer – React & Node.js

Description

Job Summary: We are looking for a Senior Full Stack Developer to join a creative and digital team focused on transforming the world through innovation and technology. Key Highlights: 1. Collaborate on digital transformation using cutting-edge technology. 2. Develop scalable and high-performance digital products. 3. Participate in architectural decisions and continuous improvement. We are knowmad mood! We are a leading digital transformation company, continuously evolving and at the forefront of technology. We were founded to drive real change through innovation and sustainable development, with a mission to deliver value to our clients and empower our talent. Comprising over 3,000 creative, digital, and innovative people connected to a shared purpose—and capable of building connections with individuals worldwide—we are a responsible, flexible team with strong adaptability to our clients’ and the market’s needs, while consistently delivering value, vision, creativity, expertise, professionalism, and passion for technology in every project. The values guiding us toward excellence are collaboration, innovation, commitment, fun, and trust. **What Do We Value?** We seek a **Senior Full Stack Developer** with solid experience developing scalable and high-performance digital products. We value candidates with an architectural mindset, strong code quality awareness, and the ability to work in distributed microservice-based environments. * **Frontend:** Solid experience with **React.js**, **Next.js**, and **TypeScript**, including reusable component creation and design systems. * **Backend:** Development with **Node.js** and **NestJS**, microservices, and clean architectures (Hexagonal, DDD, BFF). * **Databases:** Proficiency with **PostgreSQL**, **MongoDB**, and use of **Redis** for caching. * **Infrastructure:** Experience with **Docker**, deployments on **AWS / GCP / Azure**, and observability tools (Grafana, Elastic). * **Distributed Systems:** Experience with **Kafka**, PubSub, and event-driven architectures. * **Testing:** Familiarity with Jest, Playwright, and quality best practices. * **AI (as a plus, not required):** Integration of AI APIs, frameworks such as LangGraph or Vercel AI. **What Would Your Responsibilities Be?** * Develop and evolve modern web interfaces using **React / Next.js**, focusing on performance and usability. * Design, build, and maintain microservices using **Node.js** and **NestJS**. * Participate in architectural decisions and provide technical input on scalable projects. * Design and integrate messaging, caching, and persistence systems. * Collaborate on the creation and evolution of **design systems** and reusable components. * Contribute to platform observability via metrics, dashboards, and traceability. * Work alongside multidisciplinary teams (product, UX, backend, mobile). * Actively participate in code reviews, establishment of best practices, and continuous improvement of the tech stack. * (**Optional**) Integrate AI services into existing digital products when needed. **Additionally, we highly value experience and/or knowledge in:** * Prior experience developing **complex digital products**, B2C or high-traffic applications. * Experience in **performance optimization**, both frontend and backend. * Deep understanding of modern architectural patterns. * Experience with **event-driven architectures**. * Experience integrating cloud services (AWS, GCP, or Azure). * Strong grasp of **CI/CD**, automated testing (Jest, Playwright, RTL). * Ability to work in agile environments (Scrum/Kanban). **And with us, you’ll enjoy:** Full-time schedule of 8 hours per day (no compressed workweek) 2 remote workdays per week Flexible start time between **7:00 and 10:00**, plus **1 hour for lunch** Additional vacation days as compensation Hybrid on-site model: **minimum 3 days per week onsite in Madrid (Sanchinarro area)** *At* ***knowmad mood*** *we are committed to equal opportunity and respect for diversity. We implement our Equality Plan and the principle of non-discrimination across all recruitment processes.* Stay updated on our news by following us here \-\> knowmad mood