Cisco Certified Network Associate (CCNA)

• 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

• Kubernetes: EKS management, cluster upgrades and stability improvements, Infrastructure-as-Code reviews and updates, AWS support, and cost optimization.

• Designing and developing a web application for the public sector
• Setting up and executing software tests, mainly unit tests
• Technical design and implementation of requirements
• Uploading and displaying CSV files
• Communicating with business units regarding development and test support
• Technologies used: Java, Spring Boot, Spring Security, Spring Batch, Spring Cloud, Spring Data JPA and Hibernate, RESTful, JSON, React, Oracle, JUnit, Mockito, CI/CD, GitLab, Docker, Keycloak, Liquibase, BIRT, Swagger, Microservices

• Migration of backups and complete workloads to AWS and Azure, including setup and management of AKS & EKS clusters.
• Automation with Terraform & ArgoCD, CI/CD pipelines implemented with GitLab.
• System monitoring on OpenShift 4 (on-premise) with Grafana & Prometheus, use of CloudWatch and X-Ray for analysis and logging.
• Building and maintaining secure network infrastructures (VPCs, SGs, WAF, ACLs), integration of Azure Log Analytics.
• Close collaboration with infrastructure and development teams, maintenance of technical documentation with Confluence, ticket handling via Jira, and promoting cloud knowledge within the company.

• Designed and specified the technical network integration of a new business-critical application system (MUREX) in the capital markets area in a complex interface and outsourcing environment.

• Created component specifications, a catalog of measures and an implementation plan.

• Ensured proper integration of the developed results in line with the bank’s framework: IT compliance, IT security, change and release management.

• Selected and integrated a new service provider for the bank; moved critical bank applications to the provider.

• Designed, implemented and supported the new Cisco network and Fortinet security setup at the service provider data center.

• Acted as technical interface between the bank, service providers and consulting partners.

• Supported and further developed the network and security infrastructure (clients, servers, networks); performed error analysis and implemented solutions within agreed service levels.

• Analyzed and diagnosed all security and network failures, glitches and malfunctions.

• Initiated continuous improvements to ensure efficient resource use and acceptable response times for users.

• Provided network support in a financial services organization and prepared operational changes on production banking network infrastructure for both large and small projects within strict change management discipline.

• Designed, defined, tested, governed and improved engineering standards.

• Performed the role of network architect for medium to large projects involving team resources.

• Support 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 serial converters)
• Support with the integration of security technology into existing IT infrastructures
• Planning and execution of network segmentation and separation
• Transfer and implementation of solutions to other plants
• Tools used: Wireshark, Network Service Manager, PRTG, Cisco Catalyst, Nexus, HP Service Manager, FNT/Command Manager Console, ServiceNow, Confluence, Active Directory, Wingard, Securepoint FW

• Responsible for the configuration, maintenance, monitoring, troubleshooting, and optimization of the IT infrastructure, including Extreme Networks, SD-WAN, and Fortinet security solutions, at all international company locations in Europe and North America
• Development of a comprehensive strategic roadmap to optimize the network architecture, including VLANS, NAC, QoS, firewall configurations, VPNs, DPI, NGFW, threat intelligence, and SSL/TLS inspection
• Implementation of the OneIT strategy through the introduction of new technologies such as Cisco DNA Center, ExtremeCloud IQ, FortiOS, FortiManager, and FortiAnalyzer, which increased employee skills and the efficiency of the IT systems
• Integration of IT and OT systems to optimize the network and security architecture and improve operational efficiency

• Provide the Price Listing Service team with prices for all cars and vans in different markets
• Adapt market-specific requirements such as taxes, government subsidies, campaigns
• Import and synchronize new prices for all new and existing cars and store them in the Redis datastore
• Support our product and on-call duty
• Daily business, development of new features, bug fixing
• Pair programming, code review, mob programming
• Develop POCs for new ideas
• Maintain and extend the backend
• DevOps tasks
• Run Kubernetes updates
• Adjust and further develop Kubernetes resources
• Develop and adapt Helm charts
• Adapt and update ArgoCD
• Maintain, adapt, and improve CI/CD

Infrastructure, automation, IT security

• Operation and modernization of business-critical Linux infrastructure for a public-sector client: RHEL migrations, Ansible automation, container rollout (since October 2025)
• Project lead for server upgrade from RHEL 7/8 to RHEL 9 in the financial sector: project management, stakeholder communication (May 2024 – Feb. 2025)
• Project support for IT security requirements in the financial sector: gap analyses, solution design with business units (March – May 2025)
• Setup of an IdM solution (FreeIPA/RHEL IdM) for a utility company (AT), including consulting and training (Apr. – Nov. 2023)
• IT infrastructure consulting for a research team: Proxmox, SSO architecture, data sovereignty, and local AI (since Feb. 2026)

• Installation, planning, maintenance and further development of the server farm in the area of hardware and software
• Migration of live systems with minimized downtime
• Processing tickets and changes in daily business
• Documentation of changes and processes in Confluence
• Test runs in the development environment
• Configuration and administration of Linux systems
• Configuration and administration of backup systems (Dell Networker, DataDomain)
• Administration of the Checkpoint firewall

• Enhance and develop the Information Security Management System (ISMS) in compliance with ISO 27001 and TISAX standards by continuously updating and refining the ISMS to align with evolving global standards.
• Ensure that security practices and policies are integrated into all business processes to achieve and maintain certifications.
• Lead the effort to identify, evaluate and mitigate risks across the organization, setting benchmarks for security measures.
• Oversee and refine security processes, with an emphasis on incident management and rapid response by developing and enforcing policies for rapid detection, investigation and remediation of security incidents.
• Train and lead the incident response team to handle breaches effectively, minimizing impact and ensuring swift recovery.
• Implement continuous monitoring solutions to detect and respond to threats in real time.
• Conduct comprehensive security assessments for internal and external IT projects, ensuring adherence to GDPR, DORA and other relevant standards.
• Oversee security evaluations for all IT projects to ensure they comply with legal and regulatory requirements.
• Integrate security measures from the planning phase through deployment to ensure all projects uphold the organization’s security standards.
• Collaborate with project teams to address findings and ensure that security risks are managed effectively.
• Serve as the principal security advisor to the IT department and senior management, offering insights on potential security challenges.
• Facilitate a culture of security awareness throughout the organization through training and regular communication.
• Lead security initiatives that align with the organization’s long-term strategic goals.
• Establish and oversee a robust third-party risk management framework to mitigate external security threats by regularly assessing third-party security practices and compliance and developing contingency plans and mitigation strategies.
• Provide regular updates and security briefings to the executive leadership and relevant committees, highlighting recent security incidents, responses, lessons learned and recommending strategic improvements.

• Complete platform upgrade from Expo 53 to Expo 54, considering project-critical breaking changes
• Version bump of react-native 0.79.5 to 0.81.5 including consolidation, updating, and reinstalling all project-related dependencies (JavaScript, native modules, build tools, TypeScript tooling)
• Identifying and fixing incompatible libraries as well as adjusting iOS and Android configurations (Gradle, Pods, build scripts)
• Enabling and integrating the React Native New Architecture (TurboModules & Fabric) including adjusting native interfaces, build configurations, and feature flags
• Cleaning up technical debt and harmonizing platform-specific implementations to ensure long-term maintainability
• Stabilizing the project through detailed debugging, regression analysis, and adjustments to the tooling chain (Metro, Babel, TypeScript)
• Conducting comprehensive test cycles (unit, E2E, device tests) and optimizing CI/CD pipelines for Bitrise and GitLab
• Ensuring stable releases for Android & iOS in conjunction with analytics, engagement, and monitoring systems

• Building APIs that enable communication and data exchange between the BSS and the underlying network infrastructure, supporting service provisioning, activation, configuration, monitoring, and billing
• Integrating NaaS APIs with existing BSS components such as CRM, order management, and billing systems to allow seamless end-to-end service orchestration
• Automating service delivery processes including order fulfilment, provisioning, and activation through APIs to reduce manual effort and accelerate time-to-market
• Implementing API-based monitoring and management of network services for real-time performance and fault management
• Integrating NaaS APIs with billing and charging systems for accurate, flexible billing based on usage or subscription models
• Enabling customer self-service portals and APIs for customers to manage network services, view usage data, and modify subscriptions
• Integrating NaaS APIs with third-party systems and applications such as cloud service providers and other network operators
• Leading a team of approximately 22 units with over 200 people
• Delivered new services that generated a recurring gross margin of €30 million year over year

• Plan & Prepare (Site Design & Readiness): Inventory & Design: Dell PowerEdge R-Series, Aruba switches (L2/L3), notebooks/peripherals; serials/asset tags, IPv4/IPv6 addressing, VLAN-/DHCP-/DNS plan

• Runbooks/MOPs: site rollout runbook, backout strategy (<15–30 min), risk register, communication matrix; approvals via CAB/change

• Images/Packages: Golden Image (Win10/11), driver packs, BIOS/UEFI baseline; O365/Teams/OneDrive KFM; BitLocker policies; MECM/SCCM, Intune/Autopilot, MDT/WinPE

• Logistics: shipping/customs clearance, RMA/DOA, on-site spares; tools (barcode scanner, label printer), "Go-Bag" (cables, SFPs, console cables)

• Deliver (on-site implementation): End devices: swap & migration (USMT/OneDrive KFM), peripherals (ATB/BT printers, scanners, boarding gate hardware); domain join, compliance checks, O365 activation, printers/queues, network drives

• Acceptance: functional tests for DCS/CUTE/CUPPS/CUSS stations, ticketing/check-in workflows, boarding gates

• Server (R-Series): rack & stack, cabling (PDU redundancy, fiber/copper), labeling/naming; firmware/RAID (PERC), Lifecycle Controller, iDRAC network; Windows Server 2022/2025 + CIS/BSI hardening; agents (backup/AV/EDR/monitoring), time service/NTP auth, Syslog/SNMPv3

• Network (Aruba): VLANs, LACP trunks, MSTP root; PortFast + BPDU Guard at the edge; QoS (EF/AF); dual stack (v4/v6), DHCP relay. NAC/802.1X with ClearPass/Radius/TACACS+, roles + MAB fallback; guest isolation, ACLs (Guest→Mgmt deny). Telemetry: sFlow, SNMPv3, Syslog→SIEM; LLDP→inventory/CMDB

• Airport specifics: CUTE/CUPPS/CUSS terminals; DCS/Amadeus/SITA connectivity; FIDS (read-only); bag tag/boarding pass printing; changes in off-peak/night windows

• Stabilize (hypercare): first-day support, KPI tracking (login times, ticket volume, error classes), QoS fine-tuning

• Troubleshooting: Wireshark/iperf, event logs, switch counters, sFlow flows; fast incident handling as SPOC

• Knowledge transfer: short training sessions for station teams, mini-runbooks (fault/recovery)

• Close (documentation & handover): docs & CMDB: final configs (switch/server), topology/patch plans, IP tables, serial/asset lists, before/after photos

• Acceptance & sign-off: UAT protocols, functional evidence (use cases), return/reuse of old hardware

• Lessons learned: risks, standard packages, driver freeze, "known issues"

• Interfaces/communication: station IT, airport IT, SOC/NOC, ground ops/ramp/check-in, provider (SITA/Amadeus). ITSM: ServiceNow (Inc/Req/Change/KB), handover to BAU