Single Sign-On Expert

• Creating concepts and architecture for domain integration (SEAT into the VW structure)
• Domain trusts and administration
• Operation and administration of Windows 2022/ 2025 servers and domains
• Domain restructuring
• GPO and SG editing and migration
• DNS restructuring and migration

Technologies: Windows 2022, Active Directory, ADFS, AD Azure Connect, DHCP, DNS, GPO, VMWare vSphere, Hyper-V, Powershell, Jira, MS Office 365,), SCCM, VSAN Fileservices, Approximately 800 servers, 400 users

As part of preparing and providing operational support for a company succession:

• Company analysis: Analysis of the overall economic, organizational and structural situation (current status, strengths/weaknesses, potential risks)
• Process analysis: Recording and documentation of all relevant business processes (BPMN, UML) in the areas of management, finance, purchasing, sales and operations
• Process optimization: Identification of weaknesses and inefficiencies, development and operational implementation of improvement measures
• Stakeholder management: Identification and analysis of all relevant internal and external stakeholders; structured communication and coordination with former and future owners, shareholders and employees
• Change management: Supporting employees and management throughout the handover process; building acceptance and trust among all parties involved
• Governance & documentation: Preparation and handover of structured operating manuals, process documentation and an organizational manual for the new business owner
• Risk & weakness analysis: Assessment of operational and strategic risks in the handover process and development of recommendations for action
• Operational support: Interim assumption of management responsibilities; ensuring business continuity during the transition phase

Business analysis / requirements engineering for the introduction of a central authorization platform:

• Analysis of existing requirements for the use of IGA solutions (NetIQ, MidPoint) in an existing IAM cluster
• Capturing requirements as epics and user stories (JIRA) to provide a comprehensive description of the use of an IGA solution for central access control across connected platforms and applications.
• Functional solution descriptions (Confluence) for various lifecycle processes, such as Identity Lifecycle (ILC), Role Lifecycle (RLC), Structure Lifecycle (SLC), and Application Lifecycle
• RBAC: Design of a role model in the IGA solution to automate access provisioning as much as possible, capturing application and business roles
• Approach for onboarding applications to the IGA tool, integrating Keycloak (ID Provider).
• Functions and processes for recertifying entitlement objects and roles, and for assigning / removing them from personalized identities.
• Functions and processes for audit-proof documentation and reporting of managed data and processes in the IGA / IAM environment.
• Planning, execution, and documentation of QA / testing for the 1st implementation phase of the MidPoint IGA solution in the IAM cluster.
• Planning a roadmap for the step-by-step testing and introduction of the IGA solution.

• Documented complex financial reporting processes in deep-dive sessions with subject matter experts
• Analyzed and mapped the 3-tier data flow SAP – Essbase – HQ (984 account entries, triple chart of accounts)
• Identified the biggest time drains (40 % of close time)
• Evaluated technologies (AWS, Microsoft Fabric, Custom/Hybrid) with cost-benefit analysis
• Created a validation rule catalog with 351 rules as the basis for pre-submission automation
• Business case: estimated savings potential of 480–960 T€/year for the EAR region
• Hands-on implementation with Microsoft Fabric, RAG, AI agents/Tool Calling and n8n; productive use of Microsoft Copilot and Copilot Studio
• AI-supported project management workflows (minutes, tasks, knowledge synchronization)
• Stakeholder management at senior management level (EAR Accounting, IEA IT, TFSC Japan), workshops and training on AI tools

Technologies: Microsoft Fabric, Copilot Studio, Claude AI, Python, Power BI, SAP, Essbase/SmartView, Excel (VBA), Notion, SharePoint

Remote freelance role focused on Agentic AI strategy, secure application patterns, and reusable agentic workflows for a government agency.

• Development and implementation of an open-source Agentic AI strategy for a government agency, with a focus on GDPR, security, and self-hosted solutions
• Development of reusable agentic workflows and business applications that enable non-technical employees to solve business problems independently
• Implementation of nine business applications with Single Sign-On (SSO) and Azure PostgreSQL integration on Hetzner Linux servers

Techstack: Python, Streamlit, Anthropic SDK (Claude), Azure, Linux, PostgreSQL, MS SQL, Angular

• Planned and developed a CPU monitoring application for monitoring system performance and resource utilization.
• Designed and implemented a Spring Boot backend providing a REST API for processing and exposing monitoring data.
• Developed the React frontend for presenting monitoring information in a clear and user-friendly interface.
• Integrated PostgreSQL for persistent storage and management of application data.
• Containerized the application and its services using Docker Compose.
• Automated infrastructure provisioning and deployment using Terraform on AWS.
• Structured the application as a modern, maintainable system using REST-based communication between frontend and backend.
• Designed and developed a secure, scalable CPU monitoring architecture (cpu-watcher) with a dedicated collector application that streams monitoring data to the backend, reducing direct exposure of system resources.
• Designed a secure cloud infrastructure with the database isolated within a private network and OIDC-based authentication.
• Implemented Infrastructure as Code with Terraform and integrated version-controlled CI/CD pipelines to automate testing, infrastructure changes, and application deployments.
• Designed and implemented the frontend delivery architecture using AWS CloudFront.

Stack: Spring Boot · React · PostgreSQL · REST API · Docker Compose · Terraform · AWS

Maturing their API practices on both a business and technology level. My role covers strategy, architecture, developer advocacy as well as hands-on software engineering, enabling both technical teams and business leadership to adopt and act on API-centric principles effectively. Coincidentally, we also establish GitOps, DX and platform best practices with this project.

Highlights:

• Aligning executives with the initiative by clarifying strategy, replacing misconceptions and myths with facts, clarifying the value of existing assets and enabling informed decision-making
• Formulating a way forward for API Lifecycle Management at OTTO
• Driving platform progress and fostering developer engagement by hands-on engineering work towards strategic goals

API Lifecycle Management, Team Topologies, Organizational Evolution, Regulatory, Platform Advocate, Developer Platform, Communities of Practice, Terraform, Kotlin, Kafka, Kong, WSO2, Apigee, Gravitee, Backstage, AsyncAPI, OpenAPI, API Design, AWS, React, Node.js, TypeScript, Redocly, reactive programming, CDC, Golang, Gin, GitOps, DX (developer experience), stakeholder management, roadmaps, workshops, discovery.

• 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

• Opt-in RAG extension over tenant-owned data sources (SharePoint, Confluence) on existing multi-tenant enterprise AI platform
• Architecture: ADRs, solution evaluations, permission strategy, cost modeling
• End-to-end SharePoint and Confluence connectors: OAuth consent flows, token refresh, metadata sync, search integration
• Permission resolution: ACL indexing at ingestion and query-time verification (document-level security)
• Elasticsearch hybrid search (semantic + keyword) with RRF scoring
• RAG chat with context injection and source citations
• Stack: Elastic Cloud, Elasticsearch, Docker, Northflank, Next.js, React, TypeScript, Prisma, Microsoft Graph API, Atlassian REST API, OAuth 2.0

• Designed and implemented modular AI assistants for sales and business processes within the Microsoft ecosystem (Agentic AI, Copilot extensions)
• Frontend architecture and development with React + TypeScript for embedded chat and assistant surfaces (streaming UI, Hooks, React Query, OpenAPI clients)
• Enterprise-level agent development: reusable skill/agent library, MCP servers, review and compliance gates
• LLM integration into the user experience: Anthropic (Claude), OpenAI, tool use, RAG pipelines, prompt engineering, guardrails
• Architecture and code review consulting, and mentoring within the AI development team
• Integration with Microsoft Graph, Power Platform, and Azure services
• Technologies: React, TypeScript, Anthropic Claude, OpenAI, MCP, RAG, Microsoft Graph, Power Platform, Azure

• Concept, interaction and UX for XR experiences for the automotive industry
• Optimizing XR experiences
• Building experiences with AI

• 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

• Designed a migration strategy for WLS applications to BKA Cloud and Stack IT

• Created a hybrid cloud for internal testing and development with Kubernetes

• Transformed the IT landscape from an outdated monolithic architecture to a cloud-based architecture

• Integrated new CI/CD processes using Azure Pipelines

• Quadrupled the processing throughput for personnel security checks

• Migrated personnel security screening applications to Docker-based applications

• Implemented CI/deployment pipelines using Azure DevOps

• Environment: Java Springboot, Kubernetes, Oracle Weblogic, OpenID, Camunda, JUnit, TOGAF

• Led QA and test automation for a distributed industrial IoT and data-integration platform connecting shop-floor systems with enterprise applications.
• Designed and maintained automated API and UI tests using Playwright, TypeScript, and Python, covering REST APIs, authentication, resource management, integrations, permissions, and end-to-end workflows.
• Tested distributed services, data pipelines, messaging infrastructure, containerized applications, and integrations across Kubernetes, OpenShift, Docker, and Docker Compose environments.
• Performed functional, integration, regression, endurance, resilience, load, chaos, and exploratory testing across complex distributed systems.
• Used Chaos Mesh and Toxiproxy for network fault injection, latency, packet loss, and partition scenarios to validate system resilience and failure handling.
• Automated infrastructure provisioning, configuration, and environment setup with Ansible and managed deployments using Kubernetes and Helm.
• Tested integrations with industrial protocols, messaging systems, databases, HTTP/REST APIs, and external enterprise systems using simulators, emulators, and dedicated test environments.
• Worked with MQTT, Kafka, SQL databases, InfluxDB, REST APIs, OAuth 2.0, JWT, LDAP, Active Directory, OpenLDAP, mTLS, TLS, MFA, SSO, and RBAC.
• Investigated and resolved 40+ defects across backend services, integrations, distributed components, and web applications, using AI-assisted analysis with Claude to accelerate debugging, test design, and root-cause investigation.
• Improved deployment reliability through Kubernetes/OpenShift configuration and health-check tuning and monitored distributed systems using Grafana, Prometheus, and Loki.
• Collaborated with developers and product teams on sprint planning, technical refinement, quality strategy, release testing, and continuous improvement.
• Applied AI-assisted and agentic testing approaches to expand automated coverage and identify complex edge cases.