Senior Backend/Fullstack Engineer (m/f/d)

Job description

itemdrop digitizes the cloakroom: our event-tech platform from Düsseldorf handles drop-off and pick-up in seconds. Over one million check-ins, around 50 customers, and real-time payments in production, even when a thousand guests arrive at once at night. Next up: scaling across Europe. As a Senior Backend/Fullstack Engineer, you'll primarily evolve our Go services for exactly that: more venues, more peak load, new integrations, tougher reliability. Where it makes sense, you'll also pitch in on the web frontend. You'll work in a small senior team directly with our Tech Lead, help shape architecture decisions, and ship in short cycles. AI tools like Claude Code are part of our everyday work. Our tech stack: Go (Golang), Gin, OpenAPI/Swagger, MariaDB (GORM), InfluxDB, Sentry, Git & GitLab CI/CD, Docker, Linux, Angular 21 (TypeScript) and Tailwind CSS on the web frontend, Claude Code. Tasks Design, develop, and maintain scalable backend services in Go Design and implement performant, idiomatic REST APIs, including interfaces to internal and external systems as well as web and mobile clients Take responsibility for transactional data: payments and credits without data loss, even at peak load Performance and error monitoring, bug fixing, and optimization of existing services regarding performance, concurrency, and resource consumption, especially SQL queries and database interfaces Light fullstack component: implement smaller features and adjustments in the web frontend end-to-end (Angular 21 with TypeScript, step-by-step migration from Angular Material to Tailwind CSS) Ensure code quality: code reviews, unit and integration tests, best practices, and adherence to existing guidelines Contribute to architecture decisions and the further development of our CI/CD pipeline Requirements Ideally three to five years of professional experience in backend development; you have a strong command of Go and SQL Solid experience with REST and API-driven applications, from API design to consuming external APIs, for web and mobile clients Awareness of transactional data and the risks of data loss or outages You understand how LLMs and AI agents work in software development, ideally with first hands-on experience in Claude Code, Codex, or Cursor You master your tools, especially for debugging and performance measurement You write clean, tested code, work in a structured way,