CareerPlan

Senior Backend Engineer Kotlin/Spring Boot (m/w/d)

Köln, NORDRHEIN_WESTFALENFull-time2026-04-13 → 2026-10-07
Hybrid

Core

Building and operating a lean, reliable backend and integration framework for a modern, cloud-native digital energy platform.

Role type

Senior Backend Engineer (Kotlin/Spring Boot)

Builds

Cloud-native backend services, event-driven architectures, and APIs for the E WIE EINFACH energy platform.

Domain

Energy / Utilities / Cloud Infrastructure

Required skills

Kotlin, Spring Boot, AWS, REST/GraphQL API design, Infrastructure as Code, CI/CD, AI Agent-driven development

Preferred skills

AI-Native Developer Mindset, Agent-driven workflows (Claude Code, Cursor, Windsurf), DevOps fundamentals

Technologies

Kotlin, Spring Boot, AWS, GitLab, OpenAPI, OAuth2, JWT, REST, GraphQL

Responsibilities

Develop focused backend services in Kotlin/Spring Boot; Design and implement event-driven architectures on AWS; Conceive and implement REST/GraphQL APIs with versioning and auth; Integrate third-party services (payments, credit checks, notifications); Ensure end-to-end backend delivery and production readiness; Maintain Infrastructure as Code and CI/CD pipelines; Collaborate with Architecture, Operations, and QA in Agile teams.

Seniority

Senior, hands-on IC