About

Fixing computers since I was a kid. Leading IT for a BlackBerry subsidiary today.

I've been fixing computers since I was a kid. First my own, then the neighbours', then across town.

In 2013 that turned into a job at Croatian Telecom, maintaining copper lines, xDSL, and both analogue and VoIP telephony in areas outside the town. I moved to Germany in 2016 and joined Dytech in 2017 as a systems engineer, then Secusmart in 2019 as a senior IT specialist, and since 2022 I've been leading IT there. Secusmart is a BlackBerry subsidiary focused on secure mobile communications.

My rule is simple: if a task is done manually more than twice, it gets a script. PowerShell, PowerCLI, Python, Bash, whichever replaces the click.

Side effect: four iOS apps on the App Store (DNS Propagation, SMTP Tester Pro, Domain Health, HeC), each one solving a problem I hit at work. Domain Health's SSL backend grew into a free public API that anyone can curl.

Away from the keyboard: family, friends, guitar, and whichever new stack I'm poking at this week.

At a glance

Born 1992

Nationality German & Croatian

Location Krefeld, NRW, Germany

Current Role Manager, Information Technology

Company Secusmart GmbH (BlackBerry)

Experience 8+ years in IT infrastructure & management

8+

Years of experience

4+

IT management roles

7+

Professional certifications

3

Languages

Automation first

If I do it twice, I automate it.

"If you're performing a task in IT manually more than twice, it should be automated." Automation isn't a tool. It's a mindset.

Stop deleting VMware snapshots by hand

Do you have time to delete snapshots manually? I don't. PowerCLI turns hours of babysitting into one scheduled job.

snapshot-cleanup.ps1

Connect-VIServer -Server vcenter.lab -Credential $cred
Get-VM | Get-Snapshot |
    Where-Object { $_.Created -lt (Get-Date).AddDays(-7) } |
    ForEach-Object {
        Write-Host "Removing $($_.Name) on $($_.VM)"
        Remove-Snapshot -Snapshot $_ -Confirm:$false
    }

Disable inactive AD accounts on a schedule

Do you have time to search inactive AD accounts manually? I don't. A few lines of PowerShell replace hours of admin work and enforce policy consistently.

disable-inactive-users.ps1

$cutoff = (Get-Date).AddDays(-90)
Get-ADUser -Filter { Enabled -eq $true } -Properties LastLogonDate |
    Where-Object { $_.LastLogonDate -lt $cutoff } |
    ForEach-Object {
        Disable-ADAccount -Identity $_.SamAccountName
        Set-ADUser $_.SamAccountName -Description "Disabled $(Get-Date -f yyyy-MM-dd) — inactive 90d"
    }

Find the source of an AD lockout in seconds

Do you have time to investigate account lockouts manually? I don't. Parse the security log, get the source host, move on.

find-lockout-source.ps1

param([Parameter(Mandatory)][string]$User)
$dc = (Get-ADDomain).PDCEmulator
Get-WinEvent -ComputerName $dc -FilterHashtable @{ LogName='Security'; Id=4740 } |
    Where-Object { $_.Properties[0].Value -eq $User } |
    Select-Object TimeCreated, @{ n='Source'; e={ $_.Properties[1].Value } } -First 5

Skills

Technical expertise gained through hands-on IT infrastructure work.

Core competencies

Network infrastructure Expert

Server management Expert

Linux administration Expert

Windows Server Expert

Active Directory Expert

Virtualisation Advanced

High availability & clustering Advanced

Storage (SAN / NAS) Advanced

Backup & recovery Advanced

Automation & scripting Advanced

Management & security

IT project management Expert

Incident response Expert

Cybersecurity Advanced

Disaster recovery Advanced

Service management (ITSM) Advanced

Budget planning Advanced

Team leadership Proficient

Frameworks & standards

BSI IT-GrundschutzISO 27001NIS2GDPR / DSGVO

Infrastructure & networking

VMwareProxmoxCiscoExtreme NetworkspfSense / OPNsenseSophosFortinetPalo AltoFirewallsVPNBGPOSPFIP routingNAT / ACLVLANWLANSANNASOpen-E

Platforms & systems

DebianRocky LinuxWindows ServerActive DirectoryGPOExchange ServerDNSDHCPAD CSSCCM / WSUS

Automation & development

PowerShellPowerCLIPythonBashGitCI/CDDockernginxApacheFastAPIREST APIsSwiftUI

Monitoring & ops

ZabbixIcingaCheck_MKSNMPELK StackWazuhVeeam

Languages

🇭🇷 Croatian Native

🇬🇧 English Fluent

🇩🇪 German Professional working

Experience

From field technician to IT leadership.

Manager, Information Technology

Secusmart GmbH (BlackBerry)

2022 – Present

Team LeadershipStrategic PlanningBudget Management
- Team leadership and strategic IT management
- Strategic planning, budget oversight and technology roadmap development
- Network infrastructure and enterprise systems management
- Automation using PowerShell, Bash, Python and PowerCLI for VMware
- Development of internal tools with custom frontend, backend and APIs
- Streamlining processes to reduce time spent on repetitive tasks
- Security framework implementation and compliance
- Disaster recovery planning and business continuity
Senior IT Specialist

Secusmart GmbH (BlackBerry)

2019 – 2022

IT InfrastructureRouting & SwitchingVMware
- Responsible for complete IT infrastructure (OSI 1–7)
- Advanced routing & switching (BGP, OSPF, NAT, ACL, VLAN)
- LAN, WAN, SAN, WLAN, high-availability clusters
- VMware server farm management and PowerCLI automation
- Custom automation scripts using PowerShell, Bash, and Python
- Development of internal tools with web interfaces to simplify workflows
- Enterprise systems monitoring and performance tuning
- Data center operations and migration planning
IT Systems Engineer

Dytech IT Solutions GmbH

2017 – 2019

Server VirtualizationNetwork SolutionsSaaS
- Server virtualization (VMware, Hyper-V)
- Enterprise network implementation (Extreme Networks, Cisco)
- OPSI implementation for automated OS and software deployment
- Complete automation of OS rollout with necessary software packages
- Virtual systems as SaaS (Software as a Service)
- Server consolidation (Microsoft, Debian, CentOS)
- Automation scripts using PowerShell and Bash
- Backup and disaster recovery implementation
- Client-focused technical consultation
Field Technician

Croatian Telecom

2013 – 2016

xDSLNetwork DiagnosticsCustomer Support
- Maintenance and troubleshooting of copper xDSL lines, both underground and aerial
- Customer premises equipment (CPE) installation and configuration
- Using specialized test equipment including HST 3000 and Time Domain Reflectometers (TDRs) to locate cable faults
- Wi-Fi troubleshooting and optimization for business and residential customers
- Home and business network installations and configuration
- Direct customer support for technical issues
- Documentation of field work and technical interventions
- Collaborating with network operations center for complex issues

Projects

Native iOS apps I've shipped to the App Store, built to solve real problems I ran into as an IT professional.

HeC - Unofficial Hetzner Cloud

2024 – Present Live

Hetzner Cloud in your pocket.

I manage Hetzner Cloud infrastructure daily and kept hitting the same wall: any quick check meant opening a laptop. I went to the App Store hoping for a Hetzner iOS app, found one that hadn’t been updated in years and was also unofficial, and decided to build my own. HeC now gives me a live view of the whole Hetzner Cloud project, with push alerts when something’s off.

An independent, third-party app; not affiliated with Hetzner Online GmbH.

Goals

Put the Hetzner Cloud console in my pocket so I don't need a laptop for routine checks
Show live server metrics and alert on trouble before it turns into an incident
Stay 100% native SwiftUI, no web views, no shortcuts

Key features

Live dashboard with a world map of server locations and real-time CPU, disk, and network metrics
Browse servers, volumes, networks, load balancers, firewalls and DNS zones
Home-screen widgets for infrastructure and server status
API tokens stored in the iOS Keychain, unlocked with Face ID or Touch ID
Premium tier for full write control: VNC console, cloud-init editor, push alerts, batch monitoring

HeC API key login screen with Manage your Hetzner Cloud heading

All Servers list showing a Debian server in eu-central with running status

Dashboard with a dark map of Europe and counts of servers

Server detail view with general information

Create Server screen with monthly pricing

Location picker with Nuremberg selected and OS image picker with Debian

Server Metrics page with live CPU usage and disk I/O graphs

SwiftSwiftUIWidgetKitHetzner APIMobile Applications

View on App Store

Domain Health

Jun 2024 – Dec 2024 Live

Domain health analysis and security auditing, in one mobile app.

Domain Health was created to address a need I saw as an IT professional: a comprehensive tool for domain health analysis and security auditing in one mobile app. It helps administrators monitor and verify domain configurations.

Goals

Complete domain health checks to verify DNS setup
Security auditing for up-to-date protection
Convenient reports for easy documentation and troubleshooting

Key features

Real-time DNS setup and configuration checks
Security audits for SPF, DMARC, and SSL certificates
White-label PDF reports, customizable for clients or internal use

Home screen in light mode with domain input and Check Domain Health button

Home screen in dark mode with domain input and Check Domain Health button

Check history list showing previous domain scans with status icons

Domain Health Report summary with status

Nameserver checks showing glue consistency

Settings with DNS over HTTPS provider selection including Google

Company information and PDF theme customization for white-label reports

SwiftSwiftUIDNSDomain Management

View on App Store

DNS Propagation

Jul 2024 – Oct 2024 Live

Multi-provider DNS propagation checks, on your phone.

Started as a personal challenge to simplify DNS propagation verification for IT professionals. As an IT manager, I needed a tool to quickly verify DNS changes when managing domains and troubleshooting websites.

Goals

Simplify DNS verification with multi-provider checks
Offer real-time insights for webmasters and IT professionals
Create an intuitive interface for quick domain health checks

Key features

Multi-provider DNS propagation checks
Support for A, AAAA, CNAME, MX, TXT, NS, SOA, SRV records
Real-time results with response times and TTL
Intuitive status indicators with favicon support

Propagation results in light mode with provider responses across regions

Propagation results in dark mode with provider responses across regions

Query history list with domain favicons and check timestamps

Expanded history entry showing per-provider response details

Swipe-to-delete action on a history entry

Swipe-to-recheck action on a history entry

iMessage share sheet with results preview

Settings screen with theme and DNS provider customization

How-to guide with technical information on DNS record types

SwiftSwiftUIAPIsMobile Applications

View on App Store

SMTP Tester Pro

Jul 2024 – Oct 2024 Live

Mobile SMTP debugger that shows the full transaction log.

This app was created to solve a specific problem I encountered as an IT professional: the inability to view detailed SMTP transaction logs while testing email servers. No app on the market offered this critical functionality.