VPN Experts in Germany

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

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

• Cross-department collaboration with other specialist teams for operations, further development and reporting.

• Firewall vulnerability analysis.

• Firewall rule approvals.

• Troubleshooting IP communication issues in the network and firewall infrastructure.

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

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

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

Project: Process optimization & IT support in an insurance broker office.

Project activities:

• Analysis of processes and definition of requirements
• Consulting for the implementation of a cloud solution (soho)
• Installation and verification of new infrastructure HW
• Cloud installation & configuration
• Definition and creation of use cases
• Performing user acceptance tests (UAT)
• User training / training
• IT support (cloud, PC, server, printer, network)

Label: Insurance, infrastructure, configuration, training, support

Analysis and optimization of end-to-end processes in different business areas such as sales, procurement, order processing and logistics. Redesign of the ERP. Identification of optimization potential, especially in areas with media breaks and manual tasks, as well as creation of a prioritized transformation roadmap with clear business cases and implementation recommendations. Management of automation initiatives. RPA at the production site in China. Evaluation and introduction of relevant AI use cases as well as building basic AI competence in the organization. Training internal employees of the project team and supporting them in the transformation process to develop a continuous improvement culture. Close collaboration with IT and external implementation partners, reporting to senior management.

Main tasks and achievements:

• Analysis of business processes and design of automated processes
• Training and support for employees in China and Germany
• 20% cost savings in logistics
• Regular status reports to management

• Regulated environment within a German banking group (approx. 8,500 employees, hybrid cloud strategy).

• Responsible for operating, provisioning, and continuously securing business-critical platforms – including a GenAI chat application, a big data/AI platform, and data science workspaces based on Azure Virtual Desktops and VMs. Ownership of Azure DevOps projects for ShaiHulud and React2Shell, as well as BSI alerts – Security Operations improvements across the SDLC.

• Deployment responsibility for the GenAI chat application, big data/AI platform (BDAI), and data science workspaces (AVD/VM-based) in the respective landing zones.

• Deployment & release management: end-to-end responsibility for deploying portal and service applications across multiple Azure landing zones, including technical approvals, compliance with development team deployment guidelines, and ensuring ITIL-based change and release processes via ServiceNow.

• Azure landing zones & network architecture: design, provisioning, and operation of Azure landing zones for 3-tier web applications with enhanced network segmentation, VNet peering, hub-and-spoke architectures, private endpoints, and firewall integration across separate subscriptions and tenants.

• Azure DevOps governance & operations: ownership of the Azure DevOps organization, including projects, repositories, and CI/CD pipelines; implementation of governance requirements such as branch policies, approval gates, permission models, and audit-ready operating structures.

• Infrastructure as Code (Terraform): design, implementation, and operation of a modular Terraform architecture for standardized cloud infrastructure deployment, including state management, provider versioning, reusability, and policy-as-code approaches.

• CI/CD pipeline engineering: design, operation, and optimization of complex YAML-based CI/CD pipelines with multi-stage deployments, template standardization, self-hosted agents, integrated secret management, and automated quality and security checks.

• Git migration & platform consolidation: planning and execution of repository and pipeline migration from Azure DevOps to GitLab CI/CD, including automated scripts, full Git history transfer, pipeline porting, and platform consolidation.

• Container & platform operations (AKS): operation and security assessment of containerized workloads on Azure Kubernetes Service, centralization of on-premises container registries for ACR.

• OpenShift (OCP) security reviews: security assessment of code baselines, build pipelines, and deployment processes for on-premises OpenShift clusters with critical applications, and derivation of specific hardening recommendations.

• Shift-left security & DevSecOps transformation: introduction of a company-wide shift-left approach for early security integration in development and deployment processes, enabling developers to perform self-led security checks and sustainably reduce vulnerabilities before production (IDE integrations, pre-commit hooks, local scanners).

• Software supply chain security: analysis and mitigation of supply chain risks in NPM- and Yarn-based applications through dependency audits, CI/CD pipeline hardening, token rotation, and restriction of risky build and lifecycle mechanisms.

• Frontend & framework security (React / Next.js): security assessment and coordination of critical vulnerability remediation across platform applications and web frameworks, including coordination and complementary technical mitigations with all teams following BSI alerts.

• Software composition analysis (SCA): introduction and operation of automated vulnerability scans for container images, pipelines/artifacts, and third-party dependencies, including SBOM exports within CI/CD pipelines.

• SAST/DAST integration: design and piloting of static and dynamic application security tests in close collaboration with security architecture and development teams, for continuous improvement of code and runtime security, and establishing operational acceptance tests.

• Artifact & registry consolidation: analysis and consolidation of all package and container repositories for service applications and AKS workloads, aiming for a centralized, secured registry strategy with centralized vulnerability scanning and governance.

• Dependency-Track & SBOM strategy: advising the compliance board on introducing a central SBOM and vulnerability management platform to increase enterprise-wide dependency transparency and accelerate CVE response capability.

• CI/CD pipeline hardening: security analysis and cleanup of the existing pipeline landscape by removing unused pipelines, improving secrets hygiene, implementing least-privilege principles, and isolating build agent environments.

• Azure Web Application Firewall (WAF) optimization: analysis and tuning of existing Azure WAF rules (OWASP Top 10 Core Rule Set, DSR/SDC, custom rules) to defend against known vulnerabilities and exploit patterns, including reducing false positives and improving threat detection.

• Documentation & stakeholder communication: creating and maintaining technical documentation, runbooks, and architecture overviews in Jira and Confluence, as well as active knowledge transfer between operations, development, security, and compliance stakeholders.

maturing their API Practices on both, a Business and Technology level. My role encompasses 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, nodejs, typescript, redocly, reactive programming, CDC, golang, gingonic, GitOps, DX (developer experience), stakeholder management, roadmaps, workshops, discovery.

As project manager for the Odoo implementation at a small company, I was responsible for designing, implementing, and training a fully integrated CRM and accounting system. Through structured requirements analysis, precise data migration, and targeted change management, I was able to complete the rollout in just eight weeks. The project led to a significant reduction in manual tasks, faster business processes, and increased real-time transparency.

Main Responsibilities

Requirements analysis and process mapping Configuration of Odoo modules: CRM, Sales, and Accounting Data migration (Excel/CSV → Odoo) and quality control Creation of workflows, automated email rules, and dashboards Conducting training sessions and providing support after go-live Project coordination (budget, schedule, stakeholder communication)

Key Achievements

Full implementation of the Odoo suite within the set timeframe (8 weeks) 30% reduction in accounting time and 25% acceleration of the lead-to-sale flow 100% customer satisfaction after go-live, based on survey results Successful migration of 100% of existing master data without data loss Establishment of a sustainable support infrastructure (3-month post go-live support)

Impact

Improved decision-making through real-time dashboards and automated reports Increased efficiency and cost savings (≈ €8,000/month) Scalability for future growth (additional modules can be integrated seamlessly) Strengthened sales and finance departments through seamless process integration

This summary highlights how I created concrete and measurable value for the company through structured project work, technical expertise, and targeted training.

• Situation: Increasing demand for privacy-compliant AI solutions for clients in the KRITIS and mid-market sector that need to analyze sensitive media content (audio, video, documents) without sending data to public cloud LLMs.

• Task: Design, deployment, and secure operation of a fully self-hosted AI infrastructure including a custom-built digital management platform for automated media analysis.

• Action: Architected and implemented a multi-tier platform on hardened Proxmox infrastructure with frontend (Nuxt 3, Vue 3, TypeScript, Tailwind 4), backend (Laravel 13, PHP 8.4, Sanctum), data storage (PostgreSQL 16, MongoDB 7), caching/queuing (Redis 7, Laravel Queue), AI workers (Python 3.11, Whisper, DeepFace, Librosa), scheduling (Laravel Scheduler/Cron), and local LLMs (Gemma, DeepSeek, Qwen, Mistral, LLaMA, Phi) via OpenWebUI with segmented network access, API hardening, and audit logging following BSI recommendations.

• Result: Fully GDPR-compliant, on-premises AI platform with zero data leakage to third parties.

• Task: Overall responsibility as an external Head of Cyber Security / CISO-as-a-Service for the design, implementation, and continuous improvement of ISMS according to ISO 27001, BSI IT-Grundschutz, and NIS2.

• Action: Built and managed Cyber Defense Centers (CDC) with SOC operations, integrated SIEM solutions (Splunk, Graylog), established risk-based vulnerability management (Qualys, Nessus, OpenVAS), and conducted regular infrastructure, application, and physical penetration tests.

• Result: Audit-ready ISMS for multiple clients and a 60% reduction in critical vulnerabilities within 90 days.

• Task: Design and execution of NIS2 assessments and operational roll-out plans for KRITIS operators.

• Action: Developed an online assessment tool for automated identification of individual weakness profiles, implemented ISMS optimizations, penetration testing, awareness programs, GRC suite deployment, and delivered C-level presentations.

• Result: Accelerated the consulting process by 50% and successfully prepared multiple clients for NIS2 compliance.

• Task: Incident commander for crisis response, forensics, and business recovery in ransomware attacks and APT campaigns.

• Action: Coordinated with state and federal police (LKA, BKA), performed forensic analysis (OSForensics, Wireshark, Kali Linux), executed disaster recovery and BCM strategies, and developed BTC extortion response strategies.

• Result: 100% recovery rate within defined RTO windows and sustainable post-incident security architectures.

• Action: Planned, built, and operated a hardened multi-VM infrastructure (Proxmox, 15+ VMs) with web and mail servers, Graylog, OPNsense firewalls, CRM/ERP and LLM instances, network segmentation, DDoS mitigation, automated patch management, and backup strategies.

• Result: >99.5% uptime over 20+ years and zero compromises.

• Action: Designed coordinated phishing campaigns with five levels of difficulty, developed e-trainings and webinars in a PDCA cycle, and led red and blue teams.

• Result: Phishing click rate reduced from 35% to under 5% within three campaign cycles.

• Development and introduction of operational processes
• Preparation of complete documentation packages (including emergency management and operations) to meet compliance requirements
• Introduction of a workshop on IaC (Infrastructure as Code)
• Professional consulting for the project's security concept (ISMS)
• Installation and operation of Kubernetes clusters on AWS, on-prem, and Azure
• Design of hybrid cloud architecture (on-prem, Hetzner, AWS)
• Analysis and resolution of incidents and system outages
• Network changes to firewall rules, gateways, OpenVPN settings, and IPsec tunnel (pfSense)
• Professional consulting on BitBucket, Jenkins, and GitLab CI/CD pipelines
• Consulting on Ansible deployments and infrastructure automation
• Consulting on building a scalable system in the cloud (AWS / Azure)
• Technologies / Tools: Ansible, Terraform, AWS, Azure, VPN, pfSense, Jenkins, Bitbucket, Kubernetes, GitLab Runner, ISMS, Golang, Prometheus, Grafana, S3, Lambda, RDS, ECS, Cognito, OIDC, Harbor, MinIO, Postgres, Redis, Keycloak, Ceph, Proxmox, CloudFormation, PostgreSQL, Flux CD, Hetzner, IONOS, Sonatype Nexus Repository, Entra ID, Dex IdP, Pulumi

Rollout of printers and PCs

• Effective management of external service providers to ensure smooth operations.
• Planning and implementation of a global rollout for 150,000 clients.
• Carrying out a comprehensive risk analysis, including overall risk, site-specific risks, and security risks.
• Successful consolidation of two existing ServiceNow systems to optimize service management.
• Close coordination with program management to achieve the project goals.

• Delivered MVP-focused full-stack architecture for a health-sector client: Vite/React frontend, backend services on Google Cloud Run, and Supabase for database plus IAM/authentication.
• Supported product requirements engineering and prioritized cost-aware workload placement, implementing browser-side/edge computation where feasible before moving logic to backend services.

• Holistic responsibility for modernizing and expanding federal networks and upgrading critical data center and telecom infrastructure in the high-security agency environment of BDBOS
• Planning and management of the expansion of national BOS network infrastructure in the VS-NfD/KRITIS environment with technical decision authority at the architecture and component level (Cisco, Layer 2/3, WAN redundancy)
• Planning, tendering (EVB-IT/UVgO) and oversight of the upgrade of security-critical telecom infrastructure for emergency call 110/112 (ACD)
• Capacity planning, rack integration, structured cabling, power supply, cooling concept (CRAC/In-Row) and DCIM monitoring for data center expansion
• Building the IT department from scratch: structures, governance, processes, team recruiting, vendor selection and long-term IT strategy
• Planning and managing infrastructure and application migrations: migration strategies, batch planning, hypercare stabilization and rollback concepts
• Creating vendor-neutral specifications (telecom systems, signature solutions) according to EVB-IT and UVgO; contract award and vendor management
• Setting up a secure IT environment according to BSI basic protection, ISO 27001 and VS-NfD; developing IT security concepts and CMDB analyses
• Hands-on program leadership: decision papers for management and steering committees, risk management, reporting and change request control

• Processing and coordination of IT tickets (Helix, Omnitracker) incl. VIP support and remote support (Microsoft Teams, RDP, FastViewer)
• Onsite support at the main location as well as support for modern conference and meeting room technology (e.g. MeetingBoard 75 Pro)
• User and rights management in Active Directory (Active Roles), Azure AD, Exchange and MDM
• VDI support and monitoring with Citrix Director and Aruba Networking
• Endpoint management and policy administration via Ivanti
• Deployment, configuration and lifecycle management of clients (Dell notebooks, iPhones, iPads)
• Hardware rollouts for new employees incl. shipping across Germany
• Asset and license management as well as organization of site migrations

• Analysis of requirements and the current situation
• Migration of an old domain structure and Tobit to Exchange 2019 with integration to MS365
• Evaluation of implementation paths and planning for securing sensitive data
• Planning regarding BSI basic protection, the German Federal Data Protection Act (BDSG), and GDPR
• IT governance and IT security backtests
• Support with ERP setup and securing mail transfer
• Hyper-V 2016/2022, Microsoft Terminal Services Cluster, Microsoft Exchange 2019
• Office 365, Microsoft 365, Azure AD, Teams, Salesforce
• Cisco, Zyxel, and HP switches, Sophos firewalls/UTMs, SecurePoint
• Microsoft IIS 2022, IPv4/IPv6, Veeam, Wortmann online backup, NextCloud
• Services: DNS, DHCP, TCP/IP, subnetting, firewalling, routing, VoIP, Group Policy (GPO), SIEM, remote work, home office, high availability, failover, VLAN, PRTG

• Designed and implemented a Python-based ETL pipeline with the Dagster framework to transform raw energy data from heterogeneous sources using InfluxDB and visualizations in Grafana
• Defined time-based and dependency-based jobs
• Deployed to managed Kubernetes clusters using Helm
• Integrated InfluxDB Cloud
• Prepared data for use in Grafana, including cleaning, normalization, and time-based resampling in Python
• Developed dashboards and visualizations in Grafana
• Developed unit tests with mocking using pytest
• Set up a CI/CD pipeline in GitLab

Technologies: Python, Dagster, InfluxDB, Grafana, pandas, pytest, REST, CI/CD, GitLab, Container, Kubernetes, Helm, Docker, Cloud