Senior Java & Kotlin Backend Developer | Spring Boot, Quarkus, Microservices, Kubernetes, PostgreSQL
Aktualisiert am 17.04.2026
Profil
Freiberufler / Selbstständiger
Remote-Arbeit
Verfügbar ab: 17.04.2026
Verfügbar zu: 100%
davon vor Ort: 100%
Java
kotlin
Spring Boot
Quarkus
Spring Cloud
Microservices
REST API
Hibernate
PostgreSQL
Kafka
Docker
Kubernetes
AWS
Maven
Gradle
JUnit
Mockito
Git
CI/CD
GitLab
Domain-Driven Design
Event-Driven Architecture
Agile/Scrum

Einsatzorte

Einsatzorte

Cologne (+50km) Berlin (+50km) Düsseldorf (+50km)
Deutschland, Schweiz, Österreich
möglich

Projekte

Projekte

9 months
2025-08 - now

Cloud-Native Commerce Platform & Kubernetes Deployment Infrastructure (Freelance)

Senior Backend Engineer / Freelancer Java Kotlin Spring Boot ...
Senior Backend Engineer / Freelancer
  • Architecture and development of a multi-tenant e-commerce platform backend using Kotlin, Spring Boot, and PostgreSQL, with 90+ business workflows implemented via saga pattern orchestration and per-tenant database isolation
  • Implementation of event-driven microservices with Kafka/Redpanda for order processing, inventory management, and payment flows
  • REST and GraphQL API design, integrated with a Next.js frontend and AI-assisted admin tooling
  • Development of a Rust-based deployment platform running on self-managed Kubernetes (k3s) on Hetzner, including horizontal autoscaling, load balancing, and zero-config deployment workflows
  • Container orchestration with Docker, Kubernetes, and Helm; GitOps-based CI/CD pipelines
  • End-to-end technical ownership: requirements, architecture, implementation, deployment, and client delivery
  • Direct client collaboration, technical scoping, and consulting on backend architecture decisions
IntelliJ IDEA GitHub Jira Linear
Java Kotlin Spring Boot Quarkus Microservices Saga Pattern Event-Driven Architecture Kafka Redpanda PostgreSQL Redis REST GraphQL Docker Kubernetes k3s Helm Hetzner CI/CD GitHub Actions Multi-Tenancy Domain-Driven Design Next.js Agile
Gumite
Remote
2 years 1 month
2023-08 - 2025-08

Jakarta EE Migration & Microservices Platform ? Insurance Sector

Senior Software Engineer Java Java 17 Kotlin ...
Senior Software Engineer
  • Design and implementation of microservices for insurance and public sector clients (LKH, Deutsche Rückversicherung) using Java 17, Spring Boot, and Jakarta EE
  • Migration of legacy Java EE applications to Jakarta EE 10 and modern Spring Boot stack
  • Development of REST APIs and event-driven integrations via Kafka
  • Containerization with Docker and deployment to Kubernetes clusters
  • Database design and optimization with PostgreSQL and Oracle
  • Test automation with JUnit 5, Mockito, and Testcontainers; CI/CD with GitLab
  • Code reviews, technical mentoring of junior developers, agile ceremonies (Scrum)
Java Java 17 Kotlin Spring Boot Spring Cloud Jakarta EE Microservices REST Kafka PostgreSQL Oracle Docker Kubernetes GitLab CI JUnit Mockito Testcontainers Maven Agile Scrum
Deutsche Rückversicherung
Cologne
3 years 8 months
2019-12 - 2023-07

Enterprise Content Management Platform ? Java Microservices & Documentum Integration

Java Developer Java Java 8 Java 11 ...
Java Developer
  • Design and development of Java/Spring Boot microservices for enterprise content management and document workflow automation
  • Integration with OpenText Documentum via DFC and REST APIs, including custom connectors for document lifecycle, versioning, and metadata management
  • Implementation of RESTful APIs and asynchronous messaging for high-volume document processing
  • Migration of monolithic Java EE components to Spring Boot microservices architecture
  • Relational database design and performance tuning with Oracle and PostgreSQL
  • Containerization with Docker and deployment to on-premise and cloud environments
  • Test automation with JUnit, Mockito, and integration testing frameworks
  • CI/CD pipeline setup with Jenkins and GitLab
  • Collaboration with international distributed teams in agile/Scrum delivery model
  • Code reviews, technical documentation, and mentoring of junior developers

OpenText Documentum IntelliJ IDEA Jira Confluence
Java Java 8 Java 11 Spring Boot Spring MVC Spring Data Hibernate JPA Microservices REST SOAP Maven Gradle Oracle PostgreSQL Docker Jenkins GitLab CI JUnit Mockito OpenText Documentum DFC Agile Scrum Git
TechMahindra GmbH
Mannheim

Aus- und Weiterbildung

Aus- und Weiterbildung

3 years 1 month
2016-01 - 2019-01

IT / Information Technology

Diploma in Information Technology, Al Furqan Training Institute
Diploma in Information Technology
Al Furqan Training Institute

  • Software Development (Java, Object-Oriented Programming)
  • Web Development (HTML, CSS, JavaScript)
  • Database Management (SQL, Relational Databases)
  • Networking and System Administration
  • Operating Systems (Linux, Windows)
  • Computer Hardware and Troubleshooting

Position

Position


Einsatzorte

Einsatzorte

Cologne (+50km) Berlin (+50km) Düsseldorf (+50km)
Deutschland, Schweiz, Österreich
möglich

Projekte

Projekte

9 months
2025-08 - now

Cloud-Native Commerce Platform & Kubernetes Deployment Infrastructure (Freelance)

Senior Backend Engineer / Freelancer Java Kotlin Spring Boot ...
Senior Backend Engineer / Freelancer
  • Architecture and development of a multi-tenant e-commerce platform backend using Kotlin, Spring Boot, and PostgreSQL, with 90+ business workflows implemented via saga pattern orchestration and per-tenant database isolation
  • Implementation of event-driven microservices with Kafka/Redpanda for order processing, inventory management, and payment flows
  • REST and GraphQL API design, integrated with a Next.js frontend and AI-assisted admin tooling
  • Development of a Rust-based deployment platform running on self-managed Kubernetes (k3s) on Hetzner, including horizontal autoscaling, load balancing, and zero-config deployment workflows
  • Container orchestration with Docker, Kubernetes, and Helm; GitOps-based CI/CD pipelines
  • End-to-end technical ownership: requirements, architecture, implementation, deployment, and client delivery
  • Direct client collaboration, technical scoping, and consulting on backend architecture decisions
IntelliJ IDEA GitHub Jira Linear
Java Kotlin Spring Boot Quarkus Microservices Saga Pattern Event-Driven Architecture Kafka Redpanda PostgreSQL Redis REST GraphQL Docker Kubernetes k3s Helm Hetzner CI/CD GitHub Actions Multi-Tenancy Domain-Driven Design Next.js Agile
Gumite
Remote
2 years 1 month
2023-08 - 2025-08

Jakarta EE Migration & Microservices Platform ? Insurance Sector

Senior Software Engineer Java Java 17 Kotlin ...
Senior Software Engineer
  • Design and implementation of microservices for insurance and public sector clients (LKH, Deutsche Rückversicherung) using Java 17, Spring Boot, and Jakarta EE
  • Migration of legacy Java EE applications to Jakarta EE 10 and modern Spring Boot stack
  • Development of REST APIs and event-driven integrations via Kafka
  • Containerization with Docker and deployment to Kubernetes clusters
  • Database design and optimization with PostgreSQL and Oracle
  • Test automation with JUnit 5, Mockito, and Testcontainers; CI/CD with GitLab
  • Code reviews, technical mentoring of junior developers, agile ceremonies (Scrum)
Java Java 17 Kotlin Spring Boot Spring Cloud Jakarta EE Microservices REST Kafka PostgreSQL Oracle Docker Kubernetes GitLab CI JUnit Mockito Testcontainers Maven Agile Scrum
Deutsche Rückversicherung
Cologne
3 years 8 months
2019-12 - 2023-07

Enterprise Content Management Platform ? Java Microservices & Documentum Integration

Java Developer Java Java 8 Java 11 ...
Java Developer
  • Design and development of Java/Spring Boot microservices for enterprise content management and document workflow automation
  • Integration with OpenText Documentum via DFC and REST APIs, including custom connectors for document lifecycle, versioning, and metadata management
  • Implementation of RESTful APIs and asynchronous messaging for high-volume document processing
  • Migration of monolithic Java EE components to Spring Boot microservices architecture
  • Relational database design and performance tuning with Oracle and PostgreSQL
  • Containerization with Docker and deployment to on-premise and cloud environments
  • Test automation with JUnit, Mockito, and integration testing frameworks
  • CI/CD pipeline setup with Jenkins and GitLab
  • Collaboration with international distributed teams in agile/Scrum delivery model
  • Code reviews, technical documentation, and mentoring of junior developers

OpenText Documentum IntelliJ IDEA Jira Confluence
Java Java 8 Java 11 Spring Boot Spring MVC Spring Data Hibernate JPA Microservices REST SOAP Maven Gradle Oracle PostgreSQL Docker Jenkins GitLab CI JUnit Mockito OpenText Documentum DFC Agile Scrum Git
TechMahindra GmbH
Mannheim

Aus- und Weiterbildung

Aus- und Weiterbildung

3 years 1 month
2016-01 - 2019-01

IT / Information Technology

Diploma in Information Technology, Al Furqan Training Institute
Diploma in Information Technology
Al Furqan Training Institute

  • Software Development (Java, Object-Oriented Programming)
  • Web Development (HTML, CSS, JavaScript)
  • Database Management (SQL, Relational Databases)
  • Networking and System Administration
  • Operating Systems (Linux, Windows)
  • Computer Hardware and Troubleshooting

Position

Position

Vertrauen Sie auf Randstad

Im Bereich Freelancing
Im Bereich Arbeitnehmerüberlassung / Personalvermittlung

Fragen?

Rufen Sie uns an +49 89 500316-300 oder schreiben Sie uns:

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