Sr Fullstack Javascript Developer

Brief DescriptionAs part of our interview process and our commitment to building high-performing teams, we’ve partnered with The Culture Index Program to better understand work styles and team dynamics. To support this process, we kindly ask you to complete a brief survey as part of the application process when submitting your profile. It should take no more than 7 minutes, and there are no right or wrong answers. We appreciate your participation and look forward to learning more about how you might fit within our team!Culture Index Survey: https://go.cultureindex.com/p/weJLJlIGZ2DauZkoWCollectivus Holdings guides many of the most prestigious brands in the Collecting, Trading Card Game, and Hobby industries. With a century's worth of collective experience in driving product and service innovation, high-end quality standards, and elevated customer experience, Collectivus brands are among the most recognized and loved throughout the world by the communities they serve.Website: https://www.collectivusholdings.comLocations: Aarhus – Dallas – Delhi – Lisbon – Nashville – WorldwideTitle: Senior Full-Stack JavaScript Developer (Node.js / NestJS / Next.js)Job Location: Remote - USWe are seeking a Senior Full-Stack JavaScript Developer (Node.js / NestJS / Next.js) to take technical ownership of both backend and frontend architecture. This role focuses on building and maintaining scalable, secure, and high-performance web applications using Node.js, NestJS, and Next.js. You will work with a high degree of autonomy, collaborate closely with product, frontend, and infrastructure teams, and help set engineering standards while mentoring junior developers.Key ResponsibilitiesDesign, develop, and maintain backend services using Node.js, NestJS, and TypeScriptBuild, document, and optimize RESTful APIs and integrate third-party servicesDevelop and maintain frontend applications using Next.jsDesign and optimize PostgreSQL schemas, queries, and migrationsDefine and maintain API contracts between frontend and backend systemsEnsure platform security, performance, scalability, and reliabilityConduct code reviews, enforce best practices, and mentor junior developersParticipate in system architecture decisions and technical design discussionsTroubleshoot, debug, and resolve production issuesManage deployments and support applications on Linux/Ubuntu serverMaintain technical documentation and source control using Git/bitbucketQualifications5+ years of professional experience with Node.jsStrong hands-on experience with NestJS and TypeScriptSolid experience building frontend applications with Next.jsStrong understanding of HTTP, authentication, sessions, and web security best practicesHands-on experience with PostgreSQL, including schema design and query optimizationProven experience building and maintaining production-grade APIsComfortable working in Linux/Ubuntu environmentsStrong knowledge of Git workflows, debugging, and testingAbility to work independently and take end-to-end technical ownershipStrong problem-solving skills and attention to detailNice to Have (Optional)Experience with containerization (Docker) and CI/CD pipelinesFamiliarity with cloud platforms (AWS, GCP, or Azure)Experience with background jobs, queues, or event-driven systemsExposure to monitoring, logging, and observability toolsPrior experience mentoring or leading small engineering teams