Debian Experts

• Architected, Deployed and Supported hosted email solutions in Linux and Windows environments with enterprise-grade anti-spam and security architecture for service-provider environments.
• Managed Microsoft Azure environments including Virtual Machines, VNets, Storage, VPN, and Firewall configuration.
• Administered Microsoft Exchange Server (2010-2019), Microsoft Exchange Server SE, Active Directory, PKI, Hyper-V and Zimbra environments with disaster recovery planning and operational support.
• Led Microsoft 365 onboarding and migration projects from Exchange, IMAP, and Zimbra platforms to Microsoft 365.
• Prepare security and compliance to support Microsoft 365 Copilot.
• Implement information protection and data loss prevention by using Microsoft Purview.
• Implement retention, eDiscovery, and communication compliance in Microsoft Purview.
• Integrated Active Directory Domain Services (AD DS), Active Directory Certificate Services (AD CS), and Active Directory Federation Services (AD FS).
• Delivered secure hybrid infrastructure solutions integrating Microsoft Windows Server and Linux-based enterprise environments.
• Supported enterprise integration projects involving Debian, Ubuntu, CentOS, Red Hat, Barracuda ESG, Qmail and Zimbra Platforms.

• Operation and further development of the network and security infrastructure.

• Monitoring, analysis and resolution of network and security incidents.

• Cross-departmental collaboration with other teams on operations and further development, and reporting.

• Firewall vulnerability analysis.

• Firewall access requests.

• Troubleshooting IP communication issues on network and firewall infrastructure.

• Security-critical IT infrastructure, processing of personal data, compliance with legal requirements.

• Products: Palo Alto Networks Firewalls, Cisco ACI, Checkpoint Firewalls, F5

• Technologies: SDN, SDWAN, Cisco EPIC, Cisco ACI

• Extension of a Swing-based UI for recording Security Restricted Articles during baggage screening.
• Introduction of a new workflow for recording Deboarding Events.
• Extension of the reporting system for Security Restricted Articles and Deboarding Events.
• Implementation using JBoss Wildfly, PostgreSQL, spring-boot 3.x, Java 8/21, Swing, JSF, JAX-RS/Resteasy, Docker, Maven, Kiro.

Development of AI and traditional models to analyze medical and patient data, including medication analyses, diagnosis analyses, forecasts, procedure analyses, dosage analyses, comorbidity analyses, prescription analyses, patient potential analyses, referral profile analyses, and prescription analyses. Analyses in the field of Real World Evidence.

Healthcare IT, pharmaceutical industry

Tasks, responsibilities:

• Gathering customer requirements
• Planning the subproject
• Designing and defining KPIs
• Designing and developing models and visualizations of results using customer dashboards
• Developing and implementing data warehouse adaptations
• Deriving recommendations for action

Methods, technologies:

• Simulation
• Artificial intelligence
• Python
• R
• SQL
• Microsoft Power BI
• Amazon Web Services
• Elasticsearch
• PostgreSQL
• Databricks
• Multivariate statistics

Task: Operator development and observability

Technologies and skills: Kubernetes, Valkey-Operator, Crossplane, Backstage, OpenPortal, OTEL, Grafana Cloud, Azure DevOps, Artifactory, Flux, Alloy, Prometheus, Grafana, Loki, OCF, Copilot

What I did:

• Evaluated/developed Valkey-Operator
• Set up OpenTelemetry
• Integrated it with OpenPortal/Backstage/CrossPlane

• Project: ESU Windows and SQL Server Consolidation / Configuration Management in ServiceNow
• Prepared an as-is analysis of all servers worldwide
• Prepared an as-is analysis of all SQL servers worldwide
• Conducted requirements analyses for SQL and server migrations
• Coordinated requirements with partners for migrations to Hyper-V (on-premises) or Azure Cloud
• Facilitated regular status meetings (Jour Fixe)
• Developed roadmaps and solution models for server migrations
• Set up test scenarios
• Facilitated workshops for the rollout of a global admin team
• Designed data models (CMDB) in ServiceNow
• Led workshops for the CMDB data model
• Developed solution models for the CMDB
• Created end-to-end configuration documentation and work instructions for the CMDB
• Prepared reports for license management
• Defined KPIs for data quality in ServiceNow
• Created a service catalog
• Facilitated workshops to define service requests
• Acted as interface between requirements analysis and the ServiceNow development team
• Systems used: Windows 7, Windows 10, Microsoft Office 365/2010, Windows Server 20xx, SQL Server 20xx, SharePoint, Azure Cloud, Hyper-V, ServiceNow, various tools

• Restructuring of the network architecture/topology, followed by installation, setup and testing of the network at a small business.
• Resolution of server (permissions and roles) and connection problems (WAN, (V)LAN, WLAN).
• Infrastructure support and maintenance.
• Creation of documents such as manuals, architecture documents and design documents.
• Revision of manuals and technical documents, as well as creation of VBA macros.
• Use of AI and basic prompting, as well as formulation of AI requests.
• Adjustment of workflows due to legal requirements and optimization of existing workflows.
• Delivery of courses and training for adaptations, new features and changed workflows.
• Modeling basis: BPMN.
• System environment: MS Office 2019/365, Win10/11, Teams, Netgear (Switch), QNAP, Synology (NAS), Linux (Ubuntu).

• Technical leadership across hardware, firmware, and software teams; scope: hardware/firmware team (4 people) and leadership group (5 people)
• Consolidated and documented a product family that had grown over more than 15 years and aligned it with CRA compliance — from the bare-metal I/O module to the cloud interface.
• Provided the most important customer product with the essential requirements and architecture documentation within two months — for a firmware landscape that had grown over more than 15 years. It now supports the customer’s modernization strategy.
• Established a monthly reporting line to the supervisory board and executive board within three months: nine meetings since 12/2025. The report itself is versioned and built from the CI pipeline; it is based on automatically collected activity and release data instead of assessments.
• Built a container-based CI/CD infrastructure from scratch: cross-compilation, host tests, and documentation builds in one continuous pipeline.
• Introduced declarative QA gates for DevOps and development artifacts — from the start using lefthook instead of pre-commit, executed in a dedicated container image.

Technologies used: arc42, req42, tpo42, docToolchain, PlantUML, ArchiMate, C4 model, ADR, C, C++ (GTest), CMake, Bare Metal (ARM Cortex-M3/M7), OCI containers, Jenkins, lefthook, Prometheus, Grafana, SBOM, CRA, OPC, SCADA, PLC integration, IPv6 migration, Zero Trust, Sociocracy 3.0, Cynefin

• Implementation of a full-stack application with Angular as frontend framework and Java as backend language
• Use of the Swagger OpenAPI specification for REST communication between frontend and backend applications
• Control of a card printer via the Nexus Card SDK framework
• Design and implementation of card management software with web interface and JavaFX module for printer monitoring
• Use of Cucumber tests for test automation and creation of test artifacts for testing outside the development environment
• Use of Wireshark for network investigations to analyze the API of a third-party product and to check the REST API of the self-developed software

• Architected and deployed private cloud data platform on VMware vSphere, integrating Greenplum MPP, Apache Kafka, Kubernetes, and Apache Solr, and developed real-time ingestion pipelines with Kafka Connect and Schema Registry.
• Led Oracle Exadata to Greenplum migration, rearchitected data models, optimized storage, implemented RabbitMQ with Debezium for CDC, and deployed VectorDB for Generative AI.
• Designed and executed multi-cloud migration PoC across AWS, Azure, and GCP, defined KPIs for throughput, latency, and cost efficiency, executed bulk data transfers, validated analytics and streaming workloads, and delivered full-scale architecture recommendations.
• Assessed legacy on-premises infrastructure and designed modern cloud-native data platforms using Greenplum and containerized microservices, advising on scalability, disaster recovery, and high-availability.

• Owning RAG, LLM-System, ML-ops-Pipelines for various startups in Insurance, Banking, Energy (KRITIS)

• Responsible for the backlog and roadmap of a production SaaS compliance platform for the EU Deforestation Regulation (EUDR), with around 30 customers on AWS and Docker.
• Coordinated feature development and API integrations across 2 external and internal development teams.
• API integrations with the EU EUDR API and SAP.
• 70% fewer customer-reported issues, supporting ISO-27001 certification.

Red Hat OpenShift Container Platform

Scope:

• Operation and configuration of the Red Hat OpenShift Container Platform, including network, storage, and security design.
• Implementation of centralized observability solutions (Prometheus, Grafana, alerting).
• Development of CI/CD pipelines, GitOps workflows, and automation frameworks.
• Training and enablement of operations and development teams.

Result: Accelerated service delivery, transparent operational metrics, and sustainable knowledge transfer.

• Industry: B2B
• Headless frontend with AEM integration
• Special challenge: Migrating a PWA application in live operation based on .NET and legacy code; the entire application must be migrated to React and Express.js/TypeScript
• Technical frameworks: Tailwind, XML, JavaScript, Caddy, ReactJS, Express.js, REST API, JSON
• Cloudflare CDN
• Caddy server with GitHub CI/CD pipeline