André Bürger

André Bürger

IT Infrastructure
Team Lead

Windows · Linux · Monitoring · Security · Automation

Itzehoe, Germany

As technical lead of the IT infrastructure team at DRS Deutsche Retail Services AG, I am responsible for the infrastructure across three locations: from Active Directory and network segmentation to monitoring and security, automation, backup, and disaster recovery.

I work in a structured, well-documented way, communicate openly, and stay calm when coordinating complex situations.

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Expertise

Skills & Tech

Microsoft / Cloud

Windows ServerActive DirectoryDNS / DHCPMS 365Entra IDAzureIntuneAutopilotMicrosoft Cloud PKI

Virtualisation & Backup

VMware vSphereProxmox VEDockerVeeam Software ApplianceVeeam Backup for M365Veeam ONEVeeam Recovery OrchestratorAcronis Cyber Protect CloudProxmox Backup Server

Network & Security

pfSenseSophosMikroTik RouterOSNetBirdVLANsIPsec

Monitoring & Observability

CheckmkGrafanaGraylogWazuhTactical RMMUptime Kuma

Scripting & Automation

PowerShellBashAnsibleTerraformPackerGitLab CI/CDSemaphoren8n

Tooling & Services

Atlassian CloudJira Service ManagementConfluenceGitLabNextcloudAuthentikMailcow

Career

Experience

DRS Deutsche Retail Services AG Logo

IT Infrastructure Team Lead

DRS Deutsche Retail Services AG, Wilster, Germany

05/2026 - presentcurrent

Technical lead of the IT infrastructure team. Coordination and prioritisation of incoming requests and incidents, as well as further development of the infrastructure strategy across three locations.

  • Technical lead of the IT infrastructure team
  • Infrastructure coordination, including ticket triage, assignment, and prioritisation of incoming requests and incidents
  • Rebuilt the backup infrastructure with Veeam, documented the disaster recovery strategy, and created the IT emergency plan
  • Technical point of contact for Acronis Cyber Protect Cloud
  • Further development of monitoring, network, security, and backup systems
DRS Deutsche Retail Services AG Logo

IT Systems Administrator

DRS Deutsche Retail Services AG, Wilster, Germany

08/2023 - 04/2026

Focus on internal infrastructure across three locations, supplemented by assistance with deployment and support, as well as the coordination and prioritisation of incoming requests.

  • Responsibility for internal infrastructure at 3 locations
  • Internal infrastructure projects and support for requests and incidents from staff
  • Operation of monitoring, network, security, and backup systems
  • Occasional assistance with deployment and support
PERITS GmbH Logo

Apprenticeship, IT Systems Integration Specialist (IHK)

PERITS GmbH, Wilster, Germany

08/2020 - 07/2023

Three-year apprenticeship with IHK (Chamber of Commerce) qualification and broad hands-on focus across IT infrastructure. Afterwards hired as IT systems administrator until being taken on by DRS Deutsche Retail Services AG.

  • Final project: router/firewall replacement (Lancom → pfSense), VLAN segmentation, VPN migration
  • Deployed Active Directory (Windows Server) as central identity management
  • Rolled out Jira Service Management (migrated from VISOMA)
  • PBX migration from NFON to Starface, ongoing administration

Work

Selected Projects

Backup & Disaster Recovery

VeeamUpdated: October 2026

Problem

Historically grown backup setup without a documented strategy for recovery in an emergency.

Solution

New backup servers built on the Veeam Software Appliance, plus Veeam Backup for Microsoft 365, Veeam ONE, and Veeam Recovery Orchestrator. Documented the DR strategy and created the IT emergency plan.

Result

RPO and RTO defined for all production-critical VMs. Disaster recovery exercise completed successfully.

Infrastructure Support Portal

Jira Service ManagementUpdated: February 2026

Problem

Requests arrived uncontrolled through many channels, with no overview and no prioritisation.

Solution

Designed and rolled out a centralised JSM support portal as the mandatory intake channel for all teams.

Result

5-10 tickets/day in steady state. Full transparency over open cases and analytics for all stakeholders.

Monitoring Migration

Icinga → CheckmkUpdated: April 2026

Problem

Purely reactive troubleshooting, poor visibility, issues only noticed at failure.

Solution

Full migration from Icinga to Checkmk, complete rebuild of the monitoring stack.

Result

Approx. 100 hosts and 2,000+ services monitored. Proactive detection, faster troubleshooting cycles.

Customer Download Portal

NextcloudUpdated: December 2025

Problem

Many historically grown ways of delivering files to customers, confusing and error-prone.

Solution

Planned, tested, and rolled out a hosted Nextcloud instance as a unified standard for all customers.

Result

Actively used by all customers. Single, standardised channel for upload and download.

Personal

Homelab

A production-grade learning and test environment. Everything is documented, segmented, maintainable, and recoverable, with concepts that translate directly to professional environments.

Updated: October 2026

3

Sites

4

Proxmox VE Nodes

3

Proxmox Backup Server

~30

VMs (Proxmox)

10

VPS (Hetzner)

~100

Services

Architecture

  • Multi-site Active Directory with 2 DCs at separate locations and site-aware DNS resolvers
  • pfSense firewalls at 3 sites, site-to-site IPsec (routing- and policy-based)
  • 10 GBit core with LACP, VLANs & DMZ design, 36U rack with UPS
  • SSO via Authentik (OIDC/SAML), Linux login via SSSD against Active Directory
  • 3-2-1 backup: 3 PBS instances, TrueNAS Cloud Sync, Hetzner Storage Box (everything encrypted)
  • Monitoring of 58 hosts with Checkmk and Grafana, security monitoring with Wazuh, CrowdSec in the DMZ
  • Central log management with Graylog: syslog from pfSense and switches, Docker logs (GELF/TLS), Windows event logs (Beats/TLS)
  • 10 VPS at Hetzner: Matrix (Element), domain controller, Pangolin, pfSense, NetBird, Proxmox Backup Server, Mailcow, CloudPanel, and app servers
  • Golden images with Packer, PXE boot, CI/CD via self-hosted GitLab runners
  • Patch management with Uyuni, update automation with Renovate

Services

Platform, Storage & Containers

Proxmox VETrueNAS SCALEDockerCloudPanel

Monitoring

CheckmkGrafanaGraylogWazuhUptime Kuma

Identity & Access

Active DirectoryAuthentikSSSDNetBirdVault

Automation

AnsibleSemaphorePackerGitLab CIUyuniRenovaten8nTactical RMM

Apps & Services

GitLabRoyal ServerOpenProjectYouTrackZammadBookstackPaperless-ngxMailcowSynapseNextcloud

Network & Security

pfSenseUniFiMikroTikTraefikNginxPangolinCrowdSecNetBox

My racks

Get in touch

Contact

I'm not actively job-hunting, but if you have a concrete offer or just want to talk shop, I'm happy to hear from you.

mail@andrebuerger.de
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