Freelancer profile translated to English.

Description

For over 17 years, I have been involved in software development in medium and large Java projects. My focus has constantly changed over the 17 years. Currently, the focus is on Spring Boot, Angular, and Microservice projects. In the numerous projects, I have had the opportunity to continuously develop myself and expand my portfolio of technologies. Topics such as Microservices, Domain Driven Design, RestFul API, Test Driven Development are part of my daily methods and tools.

Languages

German
Native or bilingual
English
Conversational
Turkish
Native or bilingual

Workplace preferences

Can work on-site

Düsseldorf (up to 20km)

Signal Iduna
Senior Java Developer
BANKING AND INSURANCE
July 2023 - March 2025 (1 year and 8 months)
The Elpa application system is a microservices-based system that processes incoming applications from Signal Iduna. As part of this project, an existing WebSphere application was migrated to a modern microservice architecture implemented with Spring Boot, Spring Cloud, and Kafka.

Activities:
- Know-how transfer in the Spring Boot environment
- Introduction of Spring Cloud for optimizing Kafka usage
- Introduction of Spring Cloud Feign
- Refactoring of existing microservices to Spring Cloud and the latest version of Spring Boot
- Implementation of microservices based on Spring Boot and Spring Cloud technologies
- Implementation of MongoDB queries and SQL queries
- Implementation of unit and integration tests for the microservices
- Deployment of microservices into the OpenShift cluster
- Working in an agile team (Scrum)

Technologies:
Java 11 - 21, Gradle, Spring Framework, Spring Rest, Spring Boot, Spring Data, JPA, Hibernate, Spring Cloud, Spring Security, Feign Client, Kafka, Microservices, IntelliJ, JUnit 5, Mockito, Linux, Git, JSON, Scrum, Agile Project Management, Jira, Confluence, Jenkins, Sonar Cube, SCRUM, Open Shift, Kubernetes
Optica Abrechnungszentrum Dr. Güldener GmbH
Senior Java Developer
E-COMMERCE
August 2022 - June 2023 (10 months)
The Optica billing platform is an industry solution for health food stores. The system contains more than 50 microservices with an Angular web application. The system architecture is completely implemented with Spring Boot and Spring Cloud components. The microservices communicate with each other in a mesh architecture. The industry solution includes a point-of-sale system that can be used to bill prescriptions and transactions via payers (health insurance companies).

Activities:
- Implementation of fiscal TSE connection into the existing software
- Implementation of microservices based on Spring Boot and Spring Cloud technologies
- Implementation of import interfaces for customers based on Excel and Apache POI
- Implementation of complex search queries with Spring Data and JPA (Hibernate) for customer search
- Migration scripts with Flyway
- Implementation of unit and integration tests for the microservices
- Implementation of PDF documents with Thymeleaf and Spring
- Working in an agile team according to Scrum

Technologies:
Java 11, 17, 18, Gradle, Spring Framework, Spring Rest, Spring Boot, Spring Data, JPA, Hibernate, Spring Cloud, Spring Security, Feign Client, RabbitMQ, Microservices, IntelliJ, JUnit 5, Mockito, Linux, Git, JSON, Scrum, Agile Project Management, Jira, Confluence, Jenkins, Graylog, Sonar Cube, Flyway
BestSecret
Marketplace
RETAIL (SMALL BUSINESS)
June 2022 - July 2022 (2 months)
As part of the international BestSecret Marketplace project, a problem with the microservice architecture was to be solved. My task was to implement the Outbox Pattern for microservices using Confluent's Kafka Connect product.

During the assignment, different possibilities for realizing the Outbox Pattern were evaluated and implemented. The Kafka Connect product was then used.

Evaluation and implementation of the Outbox Pattern with Debezium.
Evaluation and implementation of the Outbox Pattern with Kafka Connect.
Evaluation of the feasibility of DTOs based on AVRO objects.
CI/CD setup for the deployment of Kafka Connect and its configuration in the Azure Cloud.
Setup of a Gitlab CI pipeline with Helm Charts.
Collaboration with international colleagues distributed across Europe.
Java Apache Kafka Kafka Connect Helm CI/CD Gitlab Gitlab CI Kubernetes Microsoft Azure