Proxmox Expert in Germany

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

Gronic Ident & Sign

Core technologies: Android, Jetpack Compose, Retrofit, Regula Document Reader, Adobe Sign

Android app on dedicated devices for identifications and electronic signatures at the PoS

• Development and introduction of operations processes
• Preparation of complete documentation packages (including incident management and operations support) to meet compliance requirements
• Introduction of a workshop on IaC (Infrastructure as Code)
• Technical consulting for the project security concept (ISMS)
• Installation and operation of Kubernetes clusters on AWS, on-prem, and Azure
• Hybrid cloud architecture design (on-prem, Hetzner, AWS)
• Analysis and troubleshooting of incidents and system outages
• Network adjustments for firewall rules, gateways, OpenVPN settings, and IPsec tunnels (pfSense)
• Technical 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

• Development of a SaaS platform for esports teams with roles, planning, statistics and billing
• Design and implementation of the architecture, external API integrations and operations
• Stack: Laravel 13, React 19, TypeScript, PostgreSQL, Redis and Stripe

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

• Consulting and project management to build an AI-based automation platform for market data analysis
• Automated testing of financial data
• Market data automation with Python and N8N
• AI data integration and AI learning
• Use of Ollama and Qwen
• Data organization and database management

• 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.

• Analysis of requirements and the current situation
• Migration of an old domain structure and Tobit to Exchange 2019 with connection to MS365
• Review of implementation options and planning for the protection of sensitive data
• Planning with regard to BSI Grundschutz, BDSG, and DSGVO
• 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 policies (GPO), SIEM, remote work, home office, high availability, failover, VLAN, PRTG

• Lead Architecture in an interdisciplinary architecture team covering enterprise, solution, NOOTS, cloud and security architecture as well as regulatory and European interoperability requirements.

• Public / Government

• Development and management of target architectures, principles, standards and technical guardrails; assessment of Security-by-Design, IAM, data protection and interface/integration architectures; architecture reviews, security assessments, risk analyses, and preparation of decision records, target visions, roadmaps and decision papers. Architectural knowledge and consideration of relevant AD-NOOTS requirements, particularly for IAM, authorization, secure integration and interoperability.

• Technologies / Methods: Enterprise Architecture, Solution Architecture, Security Architecture, Cloud Architecture, NOOTS / EU-OOTS, IAM, Authorization, Security-by-Design, API/Integration Architecture, Interoperability, Risk Analysis, Architecture Governance

• Security and integration requirements as well as technical decisions are structured in reliable architecture and decision artifacts.

Self-employed consulting, implementation, and support of IT infrastructures with a focus on IT security, network and server administration, virtualization, backup & recovery, IT documentation, asset management, and business continuity management.

• IT security consulting and implementation of technical protective measures
• Windows server and client support, patch management, user support
• M365 – Entra ID – MS Azure administration
• Planning, installation, and operation of LAN, WAN, WLAN, and VLAN infrastructures, Cisco, HP, Netgear, Sophos, Securepoint
• Support of virtual systems based on Hyper-V, VMware, and Proxmox
• Backup and recovery concepts including test recovery, documentation, and handover
• Introduction and maintenance of IT documentation, asset management, and inventory tracking
• Implementation of measures related to IT baseline protection, emergency manuals, and BCM
• On-/offboarding concepts with a focus on permissions, devices, data access, and handover processes

Security awareness and practical sensitization of users and IT staff

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.

• Analysis of the fiber optic market with a focus on FTTH
• Advising senior management on strategy planning for the next 10 years
• Reviewing product portfolios and services
• Identifying cost-saving opportunities
• Planning restructuring measures as part of a transformation program
• Designing a program structure "Fit For Profit" to implement the planned restructuring and meet strategic objectives

• Building an independent enterprise IT setup — cloud strategy, network, AWS landing zone, security requirements, contract negotiations.
• Migration of all applications; avoiding high contractual penalties for the client.
• Onboarding and coordination o...