Network Infrastructure Experts in Germany

As part of this project, the existing active network infrastructure was modernized and made fit for the future. The goal was to introduce a powerful, secure and scalable network and WLAN infrastructure, including a Network Access Control (NAC) solution to improve network security and centralized access control.

At the beginning of the project, a comprehensive requirements analysis was carried out, taking into account the technical, operational and security-related requirements of the hospital sites. On this basis, a technical tender was prepared for new switches, WLAN access points and the NAC solution.

The successful implementation of the project established a modern, standardized and secure network infrastructure that meets the growing requirements for availability, mobility and IT security in hospital operations.

Activities:

• Supporting the tender process, including technical evaluation of offers and bidder evaluation
• Leading and managing the entire project implementation
• Coordinating the project process with internal stakeholders, business units and hospital IT
• Managing external service providers during the implementation and installation of the systems
• Monitoring the implementation, including quality control, project acceptance and defect management
• Coordinating and managing communication between hospital IT and external service providers as part of the NAC implementation
• Managing escalations in the event of technical and organizational challenges
• Ongoing budget monitoring and control of project expenses and additional costs
• Preparing decision papers for management on project changes, additional services and risks

• Management of firewalls (Securepoint)
• Operation and maintenance of the client-server infrastructure (Windows)
• Operation and patching of IoT devices in the hazard management system (cameras, Web IOS, IP-to-serial converters)
• Support with the integration of security technology into existing IT infrastructures
• Planning and implementation of network segmentation and separation
• Transfer and implementation of solutions in other plants
• Tools used: Wireshark, Network Service Manager, PRTG, Cisco Catalyst, Nexus, HP Service, FNT/Command Manager Console, Service Now, Confluence, Active Directory, Wingard, Securepoint FW.

• Introduction of an access control solution and preparation of a tender for a visitor management system.
• As project manager, I am responsible for the successful introduction of a cloud-based access control system at two sites with approximately 4000 employees.
• Responsible for the successful implementation of the project.
• Preparation and coordination of project plans and status reports with all stakeholders.
• Preparation/coordination of an initial effort or cost estimate and related planning for the implementation of operational services.
• Identification of interfaces.
• Compliance with the budget and schedule.
• As Tender Manager / Demand Manager, I am responsible for the following specific tasks:
• Analysis of potential providers.
• Elicitation of requirements.
• Preparation and coordination of the requirements catalog.
• Preparation of an evaluation matrix.
• Preparation of tender documents.

• Gathering information
• Creating rollout wave concepts
• Coordinating employees
• Monitoring and managing activities
• Project management including analysis and reporting to the board
• Creating instructions and specifications
• Training floorwalkers
• Supporting the rollout on site
• VIP support
• Introducing SharePoint

• Documenting the current Incident Management, IT Service Request Management, Problem Management, Change Management and Service Configuration Management processes (including CMDB)
• Conducting maturity assessments for these processes based on the ITIL® 4 Maturity Model
• Analyzing the various service value streams based on the ITIL® 4 value stream model
• Agreeing on maturity levels for the assessed processes
• Developing and approving a roadmap to achieve and measure the respective maturity levels
• Presenting the approach, including milestones, to management for approval
• Managing external service providers in 1st Level Support

• Delivery of various end-customer projects in server and network infrastructure on time, in quality, and within budget.
• Project 1: Firewall renewal, replacement of an ASA firewall with a Fortinet firewall at an automotive supplier.
• Project 2: Migration of file services from dedicated servers at 5 branch locations into a central managed file service, including DHCP, directory, and print services, as well as decommissioning of the old domain controllers.
• Project 3: Renewal of the network infrastructure at the headquarters and branch locations of a logistics company and transition of the LAN, WLAN, and firewall environments into a managed network service.
• Project 4: Network renewal, replacement of the core and access switches at the headquarters of a medical technology company and transition into a managed network service.
• Project 5: Firewall renewal, replacement of an ASA firewall with a Fortinet firewall for a city.
• Environment: ASA and Fortinet firewalls, Cisco network components, ITSM Heat/Ivanti, Confluence.

• Responsible for the concept, planning, and delivery of product development for GetMyInvoices 2.0 and its subcomponent InvoiceRails
• Independently handled all aspects of the project, including concept development, writing ticket specifications, and coordinating developers
• Created, managed, and prioritized tickets to ensure all tasks were completed on time and to a high standard
• Conducted and/or coordinated tests and ensured the proper implementation of developed features and functionality
• Worked closely with developers to clarify technical requirements and ensure implementations met specifications
• Regularly reported on project progress and documented key decisions, changes, and risks
• Took the lead on all topics related to e-invoicing and Peppol, especially regarding the InvoiceRails component
• Provided internal guidance and shared knowledge about e-invoicing and Peppol with other teams and departments
• Tracked market trends and new developments in e-invoicing and Peppol to continuously adapt the product strategy
• Ensured the products’ long-term scalability and adaptability to future technological and legal changes in e-invoicing

• Fine-tuned and evaluated alternative backbone architectures for the AFFGAN handwriting style encoder to better capture writer-specific features, benchmarking against the original baseline architecture and replacing the legacy VGG19 architecture with a custom Transformer-based encoder.
• Extended the system beyond word-level synthesis to line-level handwriting generation, integrating and adapting an existing line-generation architecture to support full-sentence output.
• Deployed the handwriting generation pipeline as a web application, enabling users to select a writing style, input custom text, and instantly generate a corresponding handwriting image.
• Integrated TrOCR into a teacher–student distillation framework to evaluate and improve readability of generated handwriting, improving OCR accuracy by 20% over the baseline.
• Boosted user-study pick-rates by 40%, demonstrating a significant leap in the perceptual quality and realism of the generated handwriting compared to the baseline model.

Tech: PyTorch, Python, GANs, CNN, ViT, TrOCR, Streamlit, CUDA.

• Conceptual consulting for securing business processes
• Consulting for planning and implementing IT and IT security projects
• Security and policy checks, process optimization, contingency planning
• Project management and interim management in IT infrastructure and information security

Overview of relevant projects:

• 2025: Consulting on a DLP concept and for Digid GmbH.
• 2025: Consulting for a customer after a cybersecurity attack in which the IT infrastructure was compromised and the attacker gained M365 tenant admin rights. Investigation and recovery of the IT infrastructure. Preparation of recommendations for increasing IT security.
• 2025: Continuation of the projects listed below for Thyssenkrupp Marine Systems and Norddeutsche Landesbank.
• 2024: Preparation of a DNS concept including consulting on DNS strategy and technology, DNS design, DNS security, load balancing, reverse lookup zones and automation. Preparation of a DHCP concept including consulting on DHCP design, the central DHCP management system and automation. Consulting on the operation of the products mentioned, operating processes, and adapting the IT documentation and IT service description for Thyssenkrupp Marine Systems.
• 2024: Analysis and assessment of the network and security infrastructure established by the providers with regard to the overall architecture, consisting of the design and components. Development of proposed solutions to improve current operations, maximize performance and security, and reduce complexity. Presentation of the results, their causes and possible solutions to C-level management, including the required decision templates. Development of a SASE concept based on a Zero Trust architecture for Norddeutsche Landesbank.
• 2024: Continuation of the projects listed below for Atlas GmbH and Deutsche Vermögensberatung AG.
• 2023: Consulting on resolving findings from an IT security assessment of the IT infrastructure, conducting proof-of-concepts for DDoS protection and Digital Experience Monitoring (DEM) with Zscaler (ZIA, ZPA & ZDX), creating a new security architecture based on Zero Trust, redesigning a Cisco ISE implementation and designing a DNS security solution to protect guests and financial advisors for Atlas GmbH / Deutsche Vermögensberatung AG.
• 2023: Continuation of the projects listed below for Digid GmbH, Vaillant Group GmbH (until 09/2023), Bundesanstalt für Geowissenschaften und Rohstoffe (until 05/2023) and Union Investment IT-Services GmbH (until 07/2023).
• 2022: Preparation and review of white papers for infrastructure and security architectures, planning new network infrastructures for Deutsches Luft- und Raumfahrtzentrum.
• 2022: Development of a concept for the technical and process-related modernization of a disaster recovery plan for United Nations Volunteers.
• 2022: Development of a concept for moving measurement data to a cloud environment, introducing Network Access Control and conducting an awareness training session for Digid GmbH.
• 2022: Development of a network segmentation concept for DZ Hyp AG.
• 2022: Development of a network segmentation concept for Bundesagentur für Arbeit.
• 2021: Development of a new load balancer architecture for Bundeswehr Fuhrparkservices GmbH.
• 2021: Vulnerability scan and penetration test of a web frontend, including evaluation and preparation of recommendations for remediation, taking risk and probability of occurrence into account, for customer ifi GmbH.
• 2021: Consulting, concept development and sub-project management for introducing a Network Access Control solution (certificate authentication and MAC address bypass) and macro-segmentation (area and zone concept based on dynamic assignment of endpoints) in office and production IT for customer Vaillant Group GmbH.
• 2021: Upgrade and optimization of the LAN and WLAN infrastructure for customer United Nations Volunteers.
• 2021: Development of a target concept for modernizing the IT security infrastructure consisting of the DMZ (Cisco switches, firewalls, WSA, ESA, SMA), internet access, admin and management networks and wireless LAN, including support during implementation, for Bundesanstalt für Geowissenschaften und Rohstoffe.
• 2021: Creation of a micro-segmentation concept based on Cisco DNA and SGT and Zero Trust for Union Investment IT-Services GmbH.
• 2021: Review and update of ISMS Level-3 policies and preparation of process instructions for customer Software AG.
• 2021: Project management for the global Tec-Refresh project Meraki WLAN 2.0, coordination of outsourcing the LAN/WLAN infrastructure to a managed service provider and preparation of a WLAN concept for automated guided vehicles for customer Heraeus Infosystems GmbH.
• 2021: Project management and technical support for the “Transition of SIEM/SOC Services” project of a customer into a shared environment and assumption of the interim role of Head of Security Operations at customer Datagroup SE.
• 2021: Workshop for a future implementation of Mobile Device Management at customer Allgeier Experts Go GmbH.
• 2021: Sub-project management for introducing a rule management tool for firewalls and recertifying NAC endpoints based on 802.1x and MAB at customer Union Investment IT-Services GmbH.
• 2020: Development of a network segmentation concept for two data centers based on Cisco and VMware for Aareon AG.
• Recording and analysis of the current network architecture, including project initiation.
• Development of a concept for micro-segmentation in the data center and access network.
• 2020: Infrastructure and security architecture audit for customer Stuttgarter Versicherung AG.
• Analysis of the IT infrastructure and IT security architecture with regard to the configuration of network and security components. Additional review of contracts, process descriptions and manuals for completeness. Development of recommendations to improve the stability and operation of the infrastructure. Preparation of a network segmentation concept and project management for implementing the measures from the analysis project.
• 2020: Consulting on setting up an ISMS-Light for customer Josera foodforplanet GmbH & Co. KG.
• 2020: Security architecture consulting for customer Datagroup SE.
• Development of a future IT infrastructure and IT security architecture.
• Analysis of the current IT architecture of all 23 companies.
• Recommendations for optimizing the IT infrastructure and preparation of a comparison between a classic perimeter security concept and the Zero Trust model.
• Preparation of a security zone concept.
• Preparation of an IT infrastructure architecture in coordination with all companies.
• 2018 - 2019: Stream Lead in the Cyber Security program of Deutsche Lufthansa AG.
• Responsible for designing and implementing 9 projects in IT security infrastructure and user access management, as well as managing project managers and experts.
• Project area: Network Segmentation and Access Control.
• Project area: Security Architecture.
• Project area: Privileged, Identity & Access Management.
• Project area: Simplify User Authentication (MFA).
• Project area: Mobile & Endpoint Security.
• Project area: OT Security.
• Project area: E-enabled Aircraft.
• 2018: Security architecture consulting for customer Deutsche Lufthansa AG.
• Project management for the development, evaluation and management of the company-wide information security architecture.
• Development of a security strategy and roadmap to align the security architecture with the Zero Trust model.
• Evaluation of security solutions, services and tools available on the market.
• Definition of requirements for RfPs and evaluation of offers.
• Development, maintenance and monitoring of security architecture artifacts.
• Conducting security assessments of existing and new IT systems and security services.
• 2018: ISMS consulting for customer GLS IT Services GmbH.
• Consulting on introducing and initially operating an ISMS based on ISO27001.
• Auditing the IT environments of the GLS country companies.
• Analysis and assessment of IT security risks and derivation of required measures.
• Development of proposed solutions in coordination with the relevant stakeholders.
• Project management and transition of the ISMS to later operations.
• 2016 - 2018: Security Pre-Sales Consultant for customer Cisco Systems GmbH.
• Nationwide strategic and conceptual consulting for major enterprise customers and financial and insurance customers on Cisco and Meraki security products and services such as Firepower, WSA, ESA, Stealthwatch and ISE.
• 2017 - 2018: Design and implementation of an ISMS for customer Verivox GmbH.
• Conducting various BIAs and GAP analyses.
• Preparation of security policies based on ISO 2700x.
• Assumption of the interim role of Information Security Officer.
• 2017: Preparation of a contingency concept for VPV Lebensversicherungs-AG.
• Review and update of the IT contingency manual.
• 2016: Consulting and project management for the design of cloud and hosting services for customer Vodafone Group Services GmbH.
• Analysis and optimization of the sell-build-run process.
• Preparation of detailed-level designs for cloud products.

• Operational management of a hybrid Palo Alto Networks firewall infrastructure in an IoT environment
• Network zoning using VLANs
• Analysis, optimization, and security hardening of the rule set
• Implementation of additional firewalls in the infrastructure
• IP address management
• Security operations for Nozomi Networks’ IoT NRD solution
• Security operations for secXtreme’s honeypot infrastructure
• Managing service providers to ensure and implement required network measures
• Communication with customers and service providers in an international environment
• Technologies used: Palo Alto Networks, Panorama, Palo Alto AWS-cloud-Firewall, Nozomi Networks, Honeybox

• Led IT with 12 employees during a period of group integration, filling 3 new positions
• Analyzed IT maturity and created transparency around risks, resources and project status
• Structured and prioritized the project portfolio (group integration, ERP, NIS2, IT security)
• Engaged external service providers to close capacity gaps and initiated additional projects
• Supported the implementation of Business Central and represented IT on steering committees

• 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

• As-is assessment of the current network infrastructure and its documentation, including on-site inspections
• Independent planning of new distribution and main distribution rooms in the individual district offices (components used, rack layout, connectivity), considering the BSI IT-Grundschutz and InfoSic requirements
• Planning of new copper and fiber optic cabling, including patch panels
• Coordination with building services engineering (TGA) to ensure compliance with relevant on-site requirements
• Development of detailed execution plans and high-level concepts for the rollout of the new infrastructure
• Additional support after the components go live (hypercare phase)
• Regular communication with project management and client stakeholders

Project: Rollout of new infrastructure components

• Defined and managed the implementation of an overarching management framework with clear roles and responsibilities as part of the hardware rollout.
• Designed and established governance and control mechanisms, including the development of compliance requirements and processes for continuous quality assurance, supported by ServiceNow.
• Coordinated technical activities between service, infrastructure and specialist teams to ensure the smooth delivery and commissioning of printers and notebooks.
• Created a detailed rollout plan with specific timelines, milestones and responsibilities.
• Managed the procurement, delivery, testing, configuration, installation and on-site commissioning of hardware, including integration into existing IT systems.
• Established and continuously optimized processes for the procurement, distribution and use of printers and notebooks.
• Developed and implemented standardized provisioning processes, analyzed existing procedures, harmonized the processes involved and ensured compliance with security, compliance and quality requirements.
• Introduced agile methods to continuously improve the hardware provisioning process.
• Promoted collaboration through clear responsibilities and communication structures between internal IT teams and external service providers.
• Documented and monitored rollout progress, created rollout reports and tracked hardware implementation in real time.
• Supported change management and organized and delivered training sessions for end users.
• Created user manuals and online resources.
• Analyzed the existing hardware landscape, created hardware inventories, assessed current equipment and checked hardware compatibility.
• Developed detailed infrastructure mappings.
• Planned, organized and conducted structured interviews with key stakeholders and created requirements documents.