10/20/2026 updated
100 % available
Senior Java Backend Developer
Wrocław, Poland
Worldwide
Master of Science in EngineeringAbout me
Ich löse gerne die Herausforderungen meiner Kunden und möchte für Sie eine echte Unterstützung sein. Die Zusammenarbeit im Team macht mir Freude – gemeinsam erreicht man mehr und kann über die eigenen Grenzen hinauswachsen.
KeycloakJava (Programming Language)Spring SecurityApplication Programming Interfaces (APIs)Software QualityJUnitPostgreSQLLiquibaseNGINXOpenShiftMockitoSimple Object Access Protocol (SOAP)Systems IntegrationWebSocketSpring Boot
Backend: Java 21, Spring Boot, Spring Data, Spring Security
Architektur & Softwareentwicklung: Microservices, SOLID, Clean Code
System Integration & APIs: REST, OpenAPI, SOAP, OData, WebSockets, Apache Kafka
Datenbanken: PostgreSQL, Oracle, Redis, Liquibase, Flyway
Infrastruktur: Docker, Kubernetes, OpenShift, Nginx, Helm Charts, Argo CD
Testing: JUnit 5, Mockito, WireMock, Testcontainers, Cucumber
CI/CD & Tools: Maven, Git, SVN, Jenkins, GitLab CI/CD, SonarQube, Nexus
Security: Keycloak, OIDC, JWT, zertifikatsbasierte Authentifizierung, TLS, mTLS
Methodik: Agile, Scrum
Experience
Professional experience10+ years
Freelancer since2022
Languages
GermanFluentEnglishFluentPolishNative speaker
Project history
Development of an integration platform for a healthcare insurance project, connecting external systems to the central SAP system landscape through specialised microservices. Responsibilities included design and development of Spring Boot-based microservices, implementation of REST, SOAP, OData, and WebSocket integrations, database migrations with Liquibase, containerisation with Docker and Kubernetes/OpenShift, creation of Helm Charts, and implementation of asynchronous communication using Apache Kafka.
Development of an integrated analytical platform for managing compliance processes, including prevention of financial crime, money laundering, and international tax information exchange. Responsibilities included backend and frontend development (Java and ZK Framework), Oracle database maintenance, technical documentation, automated testing, defect resolution, and collaboration in an agile Scrum team. Achieved over 50% reduction in memory consumption through optimised data processing strategies.
Development and enhancement of software for base stations (eNodeB) used in 4G and 5G mobile networks. Responsibilities included design and implementation of new functionality for LTE network components, creation of unit and automated tests using gTest, gMock, and Erlang, execution of manual tests on real hardware, and maintenance of technical documentation.