Develop small, focused backend services in Kotlin and Spring Boot using cloud-native technologies for integrations and custom business logic
Design and implement event-driven architectures on AWS
Design, specify and implement APIs (REST and GraphQL), including versioning, documentation (e.g., OpenAPI), and authentication/authorization concepts (e.g., OAuth2, JWT)
Review and enforce provider-side API contracts to ensure backward compatibility and secure API evolution
Integrate third-party services such as payments, credit checks, notifications, or document workflows
Take end-to-end responsibility for backend delivery: development, deployment and production readiness
Implement and maintain Infrastructure as Code and CI/CD pipelines for your services in GitLab
Ensure security, reliability and observability are considered throughout the design
Work closely with Architecture, Operations and QA in Agile/Scrum teams
Use AI agents for autonomous code generation and focus on strategic reviewing, architecture and efficient human-in-the-loop processes

Several years of experience as a Backend Engineer, ideally with cloud-native architectures on AWS
Strong knowledge of Kotlin / Spring Boot and experience building API-driven integrations
AI-native developer mindset: proficient with agent-driven workflows using tools like Claude Code, Cursor (Composer) or Windsurf (Cascade)
Practical experience with DevOps fundamentals: CI/CD, Infrastructure as Code, cloud deployments
Solid understanding of API-first systems (REST/GraphQL) and asynchronous integrations
Strong ownership mentality and ability to collaborate across teams
Confident communication in German and English

Senior Backend Engineer – Kotlin, Spring Boot

Key skills