Backend Developer (Node.js/Mongo DB/Express.js)Hybrid Porto· 2–3 days/week officeABOUT THE OPPORTUNITYJoin a fast-growing, product-led tech team operating within one of Iberia's most recognised energy and mobility groups. This is a rare opportunity to work on a platform with real market impact — shaping the future of sustainable mobility infrastructure across Portugal and Spain.You will be working in a high-ownership engineering culture where backend engineers are partners in architecture decisions — not just implementers. The stack is modern, the team is collaborative, and the product is live, growing, and used at scale.PROJECT & CONTEXTThe platform sits at the intersection of EV charging, digital payments, and fleet management — a high-complexity, high-traffic environment where reliability and performance are non-negotiable. The backend team owns the full lifecycle of its services: design, build, deploy, and monitor.Day-to-day, you will:Design, build, and maintain RESTful APIs using Node.js (v18+) and Express.jsArchitect and optimise Mongo DB data models (schema design, aggregation pipelines, indexing strategies)Collaborate closely with frontend engineers, product managers, and Dev Ops on cross-functional deliveryChampion code quality through peer reviews, automated testing, and continuous improvement practicesContribute to architectural decisions and help raise the technical bar across the teamMentor junior engineers and participate actively in Agile/Scrum ceremoniesWHAT WE'RE LOOKING FORRequired Skills & Experience3+ years of professional backend development experience with the MERN stack (Mongo DB, Express.js, React, Node.js)Deep expertise in Mongo DB — schema design, aggregation framework, performance tuning, and indexingStrong experience designing and maintaining RESTful APIs at scaleSolid knowledge of SQL and relational database performance optimisationFamiliarity with Agile/Scrum methodology and active participation in sprint ceremoniesAbility to write clean, maintainable, well-tested code and conduct meaningful code reviewsStrong problem-solving skills — comfortable navigating ambiguity in a product-driven environmentProfessional proficiency in English (written and spoken) — required for daily team communicationNICE TO HAVE (Preferred Skills & Experience)Experience with Responsive Design and cross-platform frontend integrationKnowledge of Reactive Programming patterns (Rx JS or similar)Practical experience with unit testing frameworks (Jest, Mocha, or equivalent)Familiarity with containerisation (Docker) and CI/CD pipelinesExposure to cloud infrastructure (AWS, GCP, or Azure) in a production contextPortuguese language skills are a plus but not required