Jakarta EE Experts in Frankfurt

I am an experienced data engineer specializing in end‑to‑end data integration, cloud DWH architectures, and high‑quality, governed data products.

I delivered following projects and engagements as a freelancer.

• Data Migration of CRM System for AL-FA Objekt Service Gmbh
• Microsoft Software Resales Partnership

I am looking for freelance roles like: Freelance Data Engineer Cloud Data Warehouse Architect Data Modeling & Architecture Consultant MDM & Data Governance Specialist BI & Analytics Developer

Technical Focus Areas

• Data Engineering & Integration: SQL Server/SSIS, Informatica PowerCenter/IDQ, Talend, Kafka, Azure Data Factory – Delta/CDC/ELT patterns, robust pipelines, monitoring/recovery, data lineage & impact analysis, medallion architecture Bronze/Silver/Gold layers
• DWH & Cloud: Azure SQL / Data Lake / Synapse, AWS Redshift/S3, on‑prem SQL/Oracle – scalable data marts with a strong cost/benefit focus.
• Data Modeling: Atomic (Inmon) and Dimensional (Kimball), Data Vault (Linstedt), Domain‑Driven Design, clear lineage & contracts.
• MDM & Governance: Informatica MDM, IBM MDM, stewardship processes, data quality rules, survivorship/XREF, catalog/glossary, SIF/BES/REST publication.
• Analytics/BI: Power BI, SSAS, Cognos – business‑ready, maintainable data products.

Project: SCS (Settlement / Clearing Services)

Settlement platform serving multiple trading and clearing venues — counterparty risk safeguarding, settlement volume reduction, central risk management, and post-trade anonymity.

Technologies: Java 17, Spring Boot 3, Microservices, Spring Data JPA, SonarQube, Fortify (SCST), Mockito, Jenkins, OpenShift, Maven, Podman, GitHub, JIRA, Liquibase, Swagger, AMQP, Apache Camel, Terraform, PostgreSQL, Instana, Graylog.

• Identified and remediated CVEs in third-party libraries using SCA tooling, strengthening the security posture of production components.
• Maintained 90% code coverage with SonarQube, improving code quality and reducing production defects.
• Built and customized Helm charts and values.yaml configurations across 3 environments (ACT, SIMU, PROD), increasing deployment flexibility and consistency.
• Enabled mTLS for database authentication and message broker connections, enforcing encrypted, certificate-validated communication.
• Designed and deployed microservices with asynchronous, REST-based communication between components.
• Automated build and continuous integration pipelines using Maven and Jenkins.
• Used Podman and OpenShift for container orchestration and Liquibase for database version control.
• Optimized Java code and implemented EHCache-based caching, improving application performance.
• Managed application images, JAR versions, and dependencies via DBAG Artifactory Repository Manager.

• Introducing 5 different process applications for various teams

• Release planning: scope and time management

• Resource/capacity planning

• Conducting sprint planning / retrospectives

• Increment planning (multiple sprints)

• Preparing steering committee meetings / reporting to the executive board

• Coordinating / aligning with external suppliers / deliveries

• Multi-project resource planning

• Aligning with the business unit and development team

• Identifying best practices with IBM BAW

• Cost control and planning for the project team and external service providers

• Collecting KPIs using LogScale

• Analyzing application errors with LogScale / queries

• Defining user stories / aligning requirements with the business unit and development team

• Testing and defect tracking

• UI/UX design of the application

• Preparing and facilitating brown-paper workshop

• Test concept, test data, test organization, test execution

• Recording team velocity / metrics

• Executing tests

• Scripts for automated testing

• Organizing tests with the business unit and IT

• Recording and prioritizing defects

• Setting up and operating the application

• Setting up application monitoring with LogScale dashboards

• Checking health endpoints with PowerShell

• Post mortem analysis

• Setting up incident management

• Setting up problem management

• Analyzing errors using LogScale queries and dashboard

• Pre-processing data for AI

• Conducting evaluation with AI language models (Meta Llama 3.3 LLM and deepset Haystack) and RAG

• Installing runtime environments for LLMs (large language model)

• Evaluating various LLMs

• Installing RAG (retrieval augmented generation) and integrating with LLM

• Extracting unstructured data with LLM and RAG

• Project based on IBM BAW (Business Automation Workflow), WebSphere Liberty, Domea, d.3, REST, LogScale (formerly Humio), Swagger, PowerShell, JIRA, Confluence, Lucom Interaction Platform (LIP), Mattermost, Jabber

• Introduction of methods for developing and automated deployment of cloud-native software and machine learning applications in OpenShift clusters
• Development of various programs in Python
• Technologies: Kubernetes, OpenShift, Kustomize, ArgoCD, Tekton, Docker, PodMan, Airflow, IntelliJ, PyCharm, Git, Bitbucket, Jira, Confluence, Python

• Datastage 11.7, dbt, Oracle 19, Python 3.12 / PySpark 3.5, Azure GitHub, Azure DevOps, Automic
• Development of migration jobs to transfer data from the collection DWH to the new Risk Mart, as well as development of ETL pipelines to migrate historical data from the old Mart to the new Risk Mart.
• Storage of the silver layer on Hadoop and the gold layer in Oracle.
• Translation of DataStage jobs into dbt to publish reporting data in Google Cloud to a PostgreSQL database.
• Creation and optimization of complex SQL queries for data extraction from a data vault, taking into account historical data in the point-in-time tables.
• Creation of Oracle table definitions (DDL) and adjustment of existing stored procedures.
• Versioning changes in GitHub and deployment via the CI/CD portal.
• Refactoring long-running DataStage jobs into Python using PySpark to reduce server load.
• Migration of SAS scripts to PL/SQL, including new development of distribution functions that have no direct equivalent in Oracle.
• Development of Automic jobs to run DataStage pipelines and Python scripts (PySpark jobs) that control the population of the SME and institutional risk tables in the Risk Mart and perform business calculations.
• Participation in the agile process, including creating user stories, estimations, and planning in Azure DevOps.
• Handling Azure DevOps tickets and close collaboration with testers and business teams for error analysis and resolution.

• Provided coaching and support to Scrum teams to adopt and implement agile practices effectively
• Analyzed business requirements and identified IT solutions to support business goals
• Evaluated existing IT systems and processes to identify optimization opportunities
• Managed stakeholder relationships and coaching
• Facilitated Scrum ceremonies and ensured adherence to Scrum principles and practices
• Identified and implemented lean startup process optimizations to improve efficiency and effectiveness of development and business processes
• Developed and monitored daily business strategies to ensure development goals were met
• Developed and implemented OKR strategies to align team goals with company objectives
• Tools/Methodology: Jira, Confluence, Miro, PowerBI, team building & mentoring, conflict resolution, impediment resolution

• Testing the SekIDP and related components
• Test design, execution and automation, microservices, GitHub Enterprise, Eclipse, Katalon Test Platform, API Testing, Confluence 8, JIRA/Xray, Draw.io, Swagger/OpenAPI, Postman, Docker, Kubernetes, Podman, PuTTY, E-Health, Telematik, Gematik standards, EPA, E-Rezept, sektoraler IDP, encryption, XaDES, PaDES, DICOM, HL7, FHIR, IHE, ICD, SSO, SAML/Shibboleth, OAuth, smartcards, JWT, two factor authentication Android and iOS, Wireshark, BrowserStack, Cypress, gRPC, REST, SOAP, WS-Security, Linux Shell, PowerShell, SSH/SSL, Java, Kotlin, Cordova, Gradle, Groovy, Python, TypeScript

• Participate in quality workshops for requirements gathering and fit/gap analysis
• Demonstrated different QMS modules/processes with focus on customer requirements
• Design and implementation of cloud based quality system reducing manual efforts for the client
• Collaboration with cross functional teams to define and document system requirements
• Understanding the existing business process flow and suggesting improvements over moving to new quality systems
• Managed the implementation of a data migration strategy from legacy system to cloud
• Providing solution walkthrough to the business users
• Involved in integration of quality system with different third party systems
• Preparing weekly status report and presenting the same to business users and project stakeholders

• Developed a retrieval-augmented generation (RAG) application using LangChain and LangGraph for corporate document parsing, delivered as an installable Electron desktop application with local AI models via Ollama.
• Currently providing ongoing AI feature support for the Loan Pricing Tool at Hamburg Commercial Bank, with a commitment of three days per month.
• Architected Kubernetes-native solutions, including Helm chart configuration and Azure DevOps pipeline integration.

• Consulting and implementation of functional test requirements
• Responsibility for and validation of test automation solutions in an agile team
• Support for QA topics during weekly release tests
• Creating test cases using Gherkin
• Developing automated tests with Cucumber and Playwright
• Specifying and maintaining automated and manual tests

Technologies used:

• Confluence
• Jira
• Cucumber
• Playwright
• Typescript
• Java
• Git

• Design, develop, and maintain automated tests using Playwright with Python scripts, Typescript and Spring Boot
• Create test classes annotated with Spring Boot Test
• Create test scripts to cover functional, regression, and integration testing
• Ensure test automation coverage for web applications
• Collaborate with developers to identify testable requirements
• Troubleshoot automation test failures and resolve issues
• Integrate automated tests with CI/CD pipelines (e.g., Jenkins, GitLab CI/CD)
• Monitor and report test automation metrics
• Implement test data management and mocking strategies
• Ensure test reliability, stability, and maintainability
• Experience with containerization (Docker) and orchestration (Kubernetes)

• Maintenance and further development of the Java/Swing-based @rtus FormsEditor
• Design and development of a graphical formula editor based on Google Blockly to map a project-specific DSL, including parsing and code generation
• Implementation of pixel-perfect synchronization between editor and print preview to improve user experience
• Technologies: Java 17/21, Swing, JavaFX, JBoss/Wildfly, JUnit, Mockito, Blockly, JPedal, ICEPDF, Eclipse

• Further development and creation of data flows for health insurance providers
• Data management across various storage systems (DB2, MSSQL, PostgreSQL, S3, custom APIs, ...)
• Documentation and training
• Planning and deployment of NiFi 2.x (major upgrade)
• Integrating Grafana for visualization, monitoring, and alerting
• Extensive use of the NiFi API to continuously monitor the system and its components