Skills & Expertise

This list covers technologies I have worked with at varying levels, from deep expertise to practical use.

A role-specific selection of skills can be found in my CV.

Table of Contents

Hardware & Vendors

  • Servers: Dell, HPE, Lenovo
  • Storage: Synology, TrueNAS
  • Network: Fortinet, Ubiquiti, HPE Aruba, Sophos, OPNsense
  • Endpoints: HP, Dell, Lenovo, Apple
  • Remote management: KVM, iDRAC, iLO, IMM

Operating Systems

  • Linux: Ubuntu, Debian, Alpine
  • Windows: 2008 – 2025 and clients
  • Other: FreeBSD, macOS
  • Command line: Bash, PowerShell

Virtualization & Cloud

  • Hypervisors: VMware vSphere/ESXi, Hyper-V, KVM/QEMU (Proxmox)
  • Clusters: VMware vCenter, Proxmox VE Cluster
  • Containers: Docker, LXC
  • Cloud platforms: Microsoft Cloud/Azure (VMs, VNets, VPN Gateway)

Storage & Databases

  • ZFS: pools, datasets, encryption, mounting, quotas, replication
  • Filesystems & storage: Btrfs, ext4, NTFS, RAID, iSCSI, NFS, SMB/CIFS
  • Relational databases: PostgreSQL, MySQL/MariaDB, Microsoft SQL Server
  • Database tools: SQL Server Management Studio, pgAdmin, phpMyAdmin

Backup & File Transfer

  • Veeam: Backup & Replication
  • Proxmox: PMX Backup Server (PBS)
  • Synology: Hyper Backup, Active Backup for Business, Snapshot Replication, Cloud Sync
  • File transfer protocols: rsync, SCP, (S)FTP(S), WebDAV/HTTPS, rclone

Network Services & Security

  • Core protocols: IPv4, IPv6, ICMP, TCP/UDP, HTTP/S, SMTP, SNMP, DHCP, NTP
  • DNS: authoritative/recursive, MX, SPF, DKIM, DMARC, DNSSEC
  • VPN technologies: IPsec, WireGuard, OpenVPN
  • Firewall & traffic: VLAN, rules, NAT, port forwarding
  • Traffic shaping: FQ-CoDel
  • Reverse proxy & load balancing: Nginx, HAProxy – TLS termination, HSTS
  • Certificates & PKI: ACME (DNS-01), private CAs, Let’s Encrypt, lifecycle management
  • Troubleshooting: Wireshark, tcpdump, nmap
  • IDS/IPS & WAF: Suricata, Zenarmor, ModSecurity (OWASP CRS)
  • Collaborative defense: CrowdSec
  • Blocklists/threat intel: ET Open, abuse.ch, Spamhaus, DShield

Identity & Directory Services

  • Directory services: Active Directory Domain Services (AD DS)
  • Policy management: Group Policy (GPO)
  • Cloud identity: Microsoft Entra ID, Azure AD Connect/Cloud Sync
  • Authentication protocols: LDAPS, NTLM, Kerberos, SSO

System Design & Deployment

  • Virtualization clusters: Proxmox/VMware HA, quorum design, failover automation, live migration, shared storage
  • Network design: VLAN segmentation, firewall zoning, VPN deployment, multi-site connectivity, redundant uplinks
  • Installation & configuration: AD DS, CA, file & print services, RDS (Terminal Services), DHCP/DNS, IIS
  • Backup strategies: 3-2-1 design, offsite/cloud backup
  • Migrations: assess, plan and execute overnight/weekend cutovers (servers, storage, AD/Entra ID, client applications)
  • Monitoring design: logging, alerting, escalation workflows
  • Patch & lifecycle management: rolling updates, maintenance windows, test-before-prod workflows
  • System optimization: analyzing existing environments, streamlining processes, improving performance and stability
  • Documentation & handover: runbooks, architecture diagrams, knowledge transfer

Monitoring, Reliability & Performance

  • Monitoring platforms: PRTG, Checkmk, Grafana, Uptime Kuma
  • Log aggregation: Graylog, Grafana Alloy, Loki, syslog, auditd
  • Network discovery & inventory: NeDi, NetBox

Web & Application Services

  • Web servers: IIS, Apache, Nginx, OpenLiteSpeed
  • Application runtimes: Node.js, REST APIs
  • Web development: HTML, CSS, PHP, JavaScript

Hosted Applications & Services

  • File sharing & collaboration: Nextcloud, Seafile, Syncthing
  • Office & productivity suites: Collabora Online, OnlyOffice
  • Document management: paperless-ngx
  • Remote access: Apache Guacamole (gateway + VDI)
  • Identity & security: Bitwarden, Vaultwarden
  • Content management & e-commerce: WordPress, Joomla, WooCommerce
  • Source code & DevOps: GitLab
  • Business systems: Microsoft Dynamics 365 (CRM)

Collaboration & Daily Operations

  • Microsoft 365: Teams, OneDrive, Office apps
  • ITSM / ITIL tools: OTRS, Freshdesk
  • Remote access & management: SSH, RDP, MobaXterm, TeamViewer, RustDesk

AI & Productivity Tools

  • AI assistants: responsible use for brainstorming, documentation and research. Privacy-first; never on live systems.
  • Design tools: Adobe Photoshop, diagrams.net

Soft Skills

  • Problem solving: Analytical troubleshooting & root cause analysis
  • Documentation: Clear documentation & knowledge transfer
  • Prioritization: Managing tasks under pressure and deadlines
  • Reliability: Taking ownership to ensure stable, available systems
  • Adaptability: Fast learner, embracing new technologies