CentOS Experts

I designed and built a self-service AWS platform for Data Science teams with little or no infrastructure-as-code experience. A team writes about 10 lines of Python and gets a deployable stack with full SDLC release cycle that already follows the governance rules. Networking, encryption, IAM and tagging are decided by the platform, not by each team.

New teams or AWS accounts are onboarded with one pull request. Waste prevention and cost control is built into the defaults: Data scientists don't need infrastructure skills.

• Construct library (AWS CDK, Python). Built a versioned catalog of about 20 hardened constructs for being used in data-science projects with ML context
• Governance as code
• Multi-account, multi-tenant
• Golden-path scaffolding
• CI/CD and supply chain. Built reusable GitHub Actions workflows
• Release engineering
• QA with e2e, contract testing and unit test coverage with each release candidate

• 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

Goal:

Protect customer domains from spoofing by establishing and securing DMARC compliance, and ensure secure and stable operation of the Exchange and Microsoft 365 environment while keeping legitimate mail flows running smoothly.

Responsibilities:

• Project management, including reporting, customer coordination and budget responsibility
• Set up and secure DMARC, including DKIM and SPF
• Ongoing analysis of DMARC reports to detect and resolve issues early
• Replace EWS connections before Microsoft's shutdown on 01.10.2026 by switching to Microsoft Graph
• Introduce sensitivity labels in Microsoft Purview to protect sensitive information
• Automate recurring administrative tasks with PowerShell
• 3rd Level Support and ongoing administration of Exchange Online and Exchange on-premises

Technologies: Exchange Online, Exchange Server (on-premises), Microsoft 365, Microsoft Graph API, EWS, Microsoft Purview / Sensitivity Labels, DMARC, DKIM, SPF, RUA-Reporting, PowerShell, HCL Notes

Participation in the EU-funded MORANE-2 project to validate the Future Railway Mobile Communication System (FRMCS) in real-world use cases: preparation of the requirements specifications for TOBA and the associated test specifications.

Technologies: 5GS (Radio & Core), FRMCS, MCx (MCPTT, MCData, MCVideo), MC Gateway UE, MCx Priority/Security/QoS Management, ETCS, SIP, IMS

• Development of an agent-based governance platform for the automated assurance of EU AI Act compliance and ODA-compliant orchestration of AI services in complex enterprise environments.

• Design and implementation of an agent-based "Mission Control" framework (Aletheia Conductor) for autonomous state monitoring and process control.

• Development of "Compliance-as-Code" (CaC) solutions based on OPA/Rego for system-wide enforcement of regulatory guardrails.

• Integration of TM Forum ODA standards (TMF630, TMF622, TMF642) to ensure interoperability and standardization.

• Building a highly available event-driven architecture using Redpanda and CloudEvents v1.0 for near-real-time event processing.

• Implementation of an audit-proof "Evidence Chain" through cryptographic linking of trace logs in preparation for automated audits.

• Tech Stack: Java 21 (Quarkus Native), TypeScript (Next.js), Redpanda (Kafka API), CloudEvents v1.0, OPA (Open Policy Agent) & Rego, TimescaleDB, ZincSearch, Redis, TM Forum ODA, Git, GitHub, Clean Code Development, Like-C4.

• 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

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.

Designed a global SD-WAN / SASE solution (Paloalto Prisma Access or Cisco Secure Connect) and integrated it with the data center infrastructure (Cisco ACI, Cisco Catalyst/Nexus Switches, Cisco WLAN Controller, Cisco ISE)

• Clarification of project objectives, scope and the target business vision for building the AI-based knowledge database.
• Derivation of the initial architecture and implementation strategy for the Zasterbot chatbot, including separation of the MVP and further development stages.
• Development of a target business vision for building a structured knowledge database and integrating a future chatbot.
• Derivation and prioritization of use cases for information retrieval and provision by the chatbot.
• Modeling of data structures and flows for the effective organization of the knowledge database on the Base44 platform.
• Design and implementation of data models for storing and linking relevant information.
• Development of processes for extracting, analyzing and preparing raw data for the knowledge database.
• Ensuring data consistency and quality as the basis for the future chatbot.
• Planning the integration of Large Language Models (LLMs) and Retrieval-Augmented Generation (RAG) for precise and context-specific answers.
• Implementation of functions for analyzing and displaying data from the knowledge database.
• Use of the Base44 platform with JSON Schema-based entities and a flexible permission concept.
• Implementation of Deno functions for backend logic, event processing and connecting external APIs.
• Integration of OpenAI services for initial data analysis.

Further development of a software solution for managing audit applications and audit notifications according to §106d SGB V for the Association of Statutory Health Insurance Physicians in Hamburg.

• Developed numerous features, optimised performance, refactored code and analysed errors
• Refactored the development container setup
• Optimised the Gitlab-CI build pipeline
• Introduced improvements to the team workflow

Conducting a GAP analysis to assess existing security measures → identifying critical vulnerabilities

Developing an action plan that takes risk and cost-effectiveness into account

Introducing an IT maturity model based on BSI guidelines

Advising management on compliance, governance, and security strategy

Establishing internal processes for a sustainable security organization

• Analysis and optimization of the VMware environment for operation in a KRITIS environment
• Planning and implementation of updates to the VMware and hardware environment in a KRITIS environment
• Set up Skyline Health Diagnostics
• Review of the existing documentation
• Training and onboarding of new internal employees
• Support with migration and upgrade projects
• Preparations for moving scripts in the virtualization environment to GitLab
• Ticket processing with Service.Now

• PRISMA project
• Ansible automation
• Windows third-level support for Windows NT, Windows 2000, Windows 2013, Windows 2016, Windows 2019

• Responsible for Openshift/Kubernetes on-prem administration and developer support.
• Developed URP infrastructure automation with Python, Ansible, Kustomize and ArgoCD, Argo Workflow/Events stack.
• Wrote smoke and load tests for URP infrastructure utilizing Python, Kustomize and ApplicationSets.
• Helped to set up and deploy URP infrastructure in Google Cloud, GKE.
• Set up monitoring for URP and ArgoCD stack with Splunk Cloud.
• Performed system administration tasks across RedHat Linux, Kubernetes/Openshift, ArgoCD, GitLab, Bitbucket Enterprise, Kafka and MongoDB.