Java Experts in Frankfurt

Technical and commercial risk assessment for an investment project in the hardware sector (scaling potential, liability risks, operational processes) Process consulting for two SMEs in the engineering environment, with a focus on workflow digitization and PLM

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.

• Industry: Insurance, Trade, IT
• Customers & Projects: Consulting and selling insurance and similar services
• Main tasks: Insurance consulting (health insurance, retirement planning, wealth building); commercial services, inside and field sales; sales data analysis and forecasting; customer consulting and support; opening a new sales headquarters for private and business customers; business development & innovation management; business use case development; process optimization; stakeholder management; team leadership and training; preparation and delivery of trainings;
• Technologies used: Microsoft Office 365, Microsoft Teams, Jira, Draw.IO, Camunda 8, Java (8, 17,21,25), Git, Spring Boot, Spring Batch, Spring Data REST, Spring Web, Spring Security, J-Unit, Playwright, Lombock, Vaadin, H2, PostgreSQL (16, 17 18), pgAdmin, Docker, LLMs, JasperSoft Studio, JasperReports

• Elevator emergency call reorganization project: Project to evaluate and define a new technical solution for connecting elevator emergency calls for all facilities of DB InfraGO passenger stations.

• Objectives: Secure, redundant connection of all locations across Germany. Definition of the technical solution, documentation, subject-matter support and management of specialist and line organizations.

• Identification and commissioning of technical solutions.

• Management of documentation and approval of the technical solution in DB regulations.

• Definition and tracking of the roadmap for describing the solution.

• Preparation of a rollout plan to avoid shutdowns.

• Coordination and implementation of decision proposals for steering committees.

• Communication of the solution to all committees and regional areas.

The Base Services of DB InfraGO form a central data hub between the company’s IT systems. Common Data Services are developed that distribute data from source systems to a variety of downstream systems (via JMS) and make them available (via REST API). The existing service landscape based on TIBCO is being migrated to DB InfraGO’s cloud-native platform.

• Architecture design and implementation for performance-optimized bulk data processing of several million datasets at specific times during the day
• Technical specification and documentation of business requirements
• Integration of various subsystems (including SAP and Salesforce) through the reimplementation of more than 40 microservices based on Spring Boot
• Migration of TIBCO Based microservices from the Enterprise Integration Platform to the Cloud Native Platform using Spring-Boot
• Establishment of a deployment pipeline using GitLab CI/CD, Artifactory, and automated deployment to a Kubernetes environment with the help of ArgoCD
• Definition and implementation of automated unit, integration, and regression tests

Team Size: 9

Technologies/Tools: Java, Spring Boot, ActiveMQ(JMS), JUnit, Tibco Business Works, Gitlab (CI/CD), Kubernetes (Amazon AWS), ArgoCD, postgreSQL, Oracle, Postman, Hoppscotch, openAPI, Sonarqube

• Fully on-premises LLM document-examination platform for a compliance-critical banking domain: agentic LangGraph pipeline with deterministic verification, every AI judgment structured and source-anchored; ~960 automated tests, zero data egress
• GPU throughput engineering (quantized serving, speculative decoding, prefix caching): 9.5x extraction speed-up, 500+ multi-document case files per day on a single A100
• AI-native EDI/EDIFACT integration platform (~116k LOC Java 25 / Spring Boot 4, 1,900+ tests): LLM-drafted partner mappings machine-verified before go-live (DFDL conformance, field-coverage checks, dry runs), ~99.5% byte match on real customer files — replacing weeks of manual mapping per partner

• Led discovery phase and POC for Shopware to Shopify Plus migration across EMEA markets, evaluating platform suitability, technical architecture, and multi-brand/multi-country capabilities against business requirements.
• Designed reference architecture for Shopify Plus implementation incorporating headless front-end patterns (Vue.js, Nuxt.js), CMS integration (Magnolia), and Azure middleware (APIM, Functions, Logic Apps, Service Bus) for 11 EMEA markets.
• Defined migration strategy analyzing data mapping, cutover approach, and zero-downtime deployment patterns using Varnish caching, GitOps pipelines, and CI/CD orchestration across six vendor teams.
• Architected multi-tenant Shopify Plus governance model with centralized admin, localized storefront customization, and compliance controls (GDPR, data residency).
• Prototyped AI-driven search optimization (LLM.txt, JSON-LD) for product discoverability in Google AI results, demonstrating post-launch performance opportunities.
• Defined EMEA expansion roadmap for 15+ markets through C-level strategic workshops, identifying phased rollout, market-specific configurations, and resource requirements.
• Tech Stack: React, Nuxt.js, Vue.js, Magnolia CMS, Shopware, Shopify Plus, Azure (APIM, Functions, Logic Apps, Service Bus, Front Door), Varnish, SAP, MS Dynamics, Docker, Kubernetes, GitHub Actions, PostgreSQL, Kafka

The combined experience from recent project years shows that I have two passions: on the one hand, working in and for organizations to develop new, innovative products, ideally as part of a digitalization strategy or business development – as well as the closely related expertise in change and transformation processes as part of holistic organizational consulting. For this purpose, I established the Change Bakery and Product Validators offerings. On the other hand, my heart and mind are driven to find my own products, evaluate markets and potential, and test ideas. I am currently working independently and part-time alongside ongoing projects on a product idea related to mental health and have founded Therapymate.

• Introduction of 5 different process applications for different teams

• Release planning: scope and time management

• Resource/capacity planning

• Conducting Sprint Planning / retrospectives

• Increment planning (several sprints)

• Preparation of Steering Committee meetings / reporting to the Board

• Coordination / alignment with external suppliers / deliveries

• Resource planning for multiple projects

• Coordination with business department and development team

• Identification of best practices with IBM BAW

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

• Collection of KPIs using LogScale

• Analysis of application errors with LogScale / Queries

• User Story definitions / coordination of requirements with the business department and development team

• Testing and defect tracking

• UI/UX design of applications

• Preparation and moderation of Brown-Paper workshops

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

• Collection of team velocity / metrics

• Test execution

• Script for automated testing

• Test organization with business department and IT

• Recording and prioritization of defects

• Establishment and operation of the application

• Establishment of application monitoring with LogScale Dashboards

• Checking health endpoints with PowerShell

• Post Mortem analysis

• Establishment of Incident Management

• Establishment of Problem Management

• Analysis of errors using LogScale Queries and Dashboard

• Pre-processing of data for AI

• Evaluation using AI language models (Meta Llama 3.3 LLM and deepset Haystack) and RAG

• Installation of runtime environments for LLMs (Large Language Model)

• Evaluation of various LLMs

• Installation of RAG (Retrieval Augmented Generation) and integration with LLM

• Extraction of 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

• Responsible for the concept, planning, and delivery of product development for GetMyInvoices 2.0 and its subcomponent InvoiceRails
• Independently handled all aspects of the project, including concept development, writing ticket specifications, and coordinating developers
• Created, managed, and prioritized tickets to ensure all tasks were completed on time and to a high standard
• Conducted and/or coordinated tests and ensured the proper implementation of developed features and functionality
• Worked closely with developers to clarify technical requirements and ensure implementations met specifications
• Regularly reported on project progress and documented key decisions, changes, and risks
• Took the lead on all topics related to e-invoicing and Peppol, especially regarding the InvoiceRails component
• Provided internal guidance and shared knowledge about e-invoicing and Peppol with other teams and departments
• Tracked market trends and new developments in e-invoicing and Peppol to continuously adapt the product strategy
• Ensured the products’ long-term scalability and adaptability to future technological and legal changes in e-invoicing

Statistical Forecasting Algorithm

• Improvement of an statistical probabilistic forecasting algorithm for sales + evaluation
• Migration from R/On-premise to Python/Snowflake
• Productionalization on Snowflake in cooperation with data engineers & DevOps

Monitoring Dashboard

• Data engineering for preparation & provisioning of necessary data/resources on Snowflake
• Development & deployment of a Streamlit dashboard in Snowflake

ML-based Probabilistic Forecasting on Vertex AI

• Development of a ML-based probabilistic forecasting algorithm from scratch
• Implementation of MLOps pipeline in Kubeflow on Google Cloud Vertex AI

Tech Stack: Python, Snowflake/Snowpark, R, Streamlit, Gitlab/Gitlab CICD, Terraform, Google Cloud, Vertex AI (aiplatform SDK, gcloud CLI, feature store, model registry, etc), kubeflow

• Error analysis and fixes including performance optimization of the in-house developed platform API
• Change and incident management in day-to-day operations
• Responsible for compliance with security and compliance requirements
• Vendor management for software development and maintenance
• Planning and execution of migration of legacy services to a cloud native platform

Role in the project: project staff, implementation team

Used skills: requirements analysis, IT service and application management, IT operations, error analysis and performance optimization, software maintenance and lifecycle management

Project environment: Cloud Native Platform (Kubernetes, Crossplane, AWS, ArgoCD, Grafana)

• Development, maintenance, and execution of „Regulatory Transaction Reporting“ (MiFIR & Dodd-Frank)
• Business and IT specification, testing, and business analysis in the banking systems environment of Summit, Murex, and Calypso, particularly in migration projects.
• Development, maintenance, and execution of P&L and risk reporting.
• Liaison between the business department and IT in an agile project environment.

• Conducting and evaluating web analyses
• Creating and editing tags and scripts in the area of tag management as well as banners and other client-side web elements in the area of consent management
• Technologies used in development: Tealium, JavaScript, IntelliJ, Git, Android Studio, Selenium, Appium, Adobe Analytics, Power Automate, Power App