Please note - this is a hybrid role, with 3 days per week working from our office in Warsaw.AboutWe are looking for an experienced Node.js Developer to join our web development team. In this role, you will build and maintain server-side applications and APIs. You should have strong JavaScript skills, good knowledge of backend systems, and experience working with databases and cloud platforms.ResponsibilitiesBuild and maintain server-side applications using Node.jsDesign and develop REST and GraphQL APIsImprove application speed, scalability, and securityConnect backend systems with front-end parts and external servicesWork closely with product managers, designers, and other developersWrite clean, easy-to-read, and well-documented codeTake part in code reviews and team discussionsFind and fix issues in production systemsKeep learning new technologies and follow best practicesRequirementsStrong experience with Node.js and JavaScript (ES6+)Experience with Express.js or similar Node.js frameworksGood understanding of asynchronous and event-based programmingKnowledge of REST APIs, WebSockets, and GraphQLExperience with databases such as MongoDB, PostgreSQL, or MySQLExperience using version control tools like GitStrong problem-solving skills and attention to detailExperience writing unit tests using tools like Mocha or ChaiKnowledge of authentication systems, including OAuth and OpenIDGood understanding of data structures, algorithms, and software designStrong analytical and debugging skillsNice to HaveExperience with cloud platforms such as AWS, Google Cloud, or AzureKnowledge of microservices architectureExperience with testing tools like Jest or MochaFamiliarity with Agile or Scrum ways of workingExperience building RAG applications and working with vector databasesExperience setting up CI pipelines for testing and code quality checks