Senior Full Stack Engineer (d/f/m)

Join the Advertising team, a cross-functional team based in our lovely new Berlin office, developing exciting products to make advertising smarter on Kleinanzeigen and improve the experience for the end user. You will work on end-to-end product development, contributing across frontend and backend systems, and help build scalable solutions for our Advertising platform, a key initiative to unify independent platforms into a single, robust ecosystem. You will report directly to the Engineering Manager of the team. This is a hybrid role, and our office is based in Berlin Charlottenburg. Who You Are: You have proven experience in Growth Product Management, ideally with subscription models or B2B/SMB funnels. Strong believer in teamwork, ownership, and collaboration 5+ years of experience in software engineering, including both backend and frontend development Strong backend experience with Java or Kotlin and Spring Boot ecosystem Solid frontend experience with React or Next.js and TypeScript Experience designing and building scalable APIs and microservices Hands-on experience with relational databases (PostgreSQL, MySQL, etc.) Strong understanding of cloud environments (AWS preferred) Familiarity with CI/CD pipelines and modern development workflows (e.g., GitHub Actions, Jenkins) Experience with testing frameworks (e.g., Jest, Vitest, Playwright, or backend equivalents) Understanding of distributed systems, messaging systems (e.g., Kafka), and observability tools (Grafana, Datadog) Comfortable working in Agile environments Bachelor’s degree in Computer Science, Engineering, or equivalent practical experience Nice to HaveExperience in AdTech / advertising platforms Experience with data workflows (Airflow, DBT) Familiarity with Astro or modern frontend tooling beyond React ecosystem Strong focus on UX and product thinking What You’ll DoBe part of a friendly, multicultural team, working in an Agile environment Take ownership of the full development lifecycle, from architecture to QA and deployment Design, build, and maintain scalable backend services using modern Java/Kotlin frameworks Develop and maintain modern frontend applications using TypeScript, React or Next.js Collaborate closely with Product Managers, Designers, and other Engineers to deliver high-quality features Build clean, efficient, and reusable code following best practices and coding standards Optimize application performance and scalability across both frontend and backend layers Design and implement RESTful APIs and microservices architectures Ensure code quality and maintainability through testing, code reviews, and best practices Contribute to system design, architecture decisions, and technical strategy Write clear technical documentation for systems, APIs, and architecture Be an active part of our Engineering community to drive continuous improvement At Kleinanzeigen, we care about our people — their wellbeing, growth, and life beyond work. Our benefits are designed to support you holistically, giving you flexibility and opportunities to thrive. ✨ Flexibility Flexible working time (hybrid) 20 days “work from anywhere” Paid additional parental leave for both parents Extra paid days off for special occasions (e.g. your wedding or a move) ❤️🩹 Wellbeing & Support Confidential support & coaching for you and your loved ones Annual company sports events Pension and life insurance 📚 Growth & Development Personal development budget Learning opportunities to grow your skills and career 🛍️ Perks & Everyday benefits Corporate benefits and exclusive discounts An attractive referral program Transportation allowance Free shipping on Kleinanzeigen Direktkauf Kleinanzeigen is an equal opportunity employer that values diversity and inclusion. We welcome people of all backgrounds, races, religions, colours, national origins, gender identities, sexual orientation, ages, marital status, or disability. If this role sparks your interest but you’re not sure you meet every single requirement, we’d still love to hear from you anyway.