István Csémi István Csémi
System Administrator · DevOps · Cybersecurity
I build, secure and run Linux infrastructure — from a hybrid Proxmox & VPS homelab to honeypots and security automation. I break systems so they hold up, and keep them running so you don't have to.
MSc student and working System Administrator, fluent across Linux infrastructure, network security and Microsoft 365 — happiest when something needs hardening.
My day-to-day spans L1 and L2 support, joining PCs to Entra ID, creating Microsoft 365 accounts and migrating local profiles into 365. At home I run a hybrid Proxmox + VPS environment with Docker, VLAN segmentation, VPN and automated threat detection with CrowdSec — plus Cowrie honeypots I use to watch real-world attacks and see how bots operate.
I practise ethical hacking on HackTheBox & TryHackMe, and I'm actively learning Kubernetes and Ansible. I'm currently employed and open to part-time work — mainly in system administration, DevOps and cybersecurity, and I'm happy to take on project-based work too. Evenings and weekends.
Three things I do, end to end
Not just theory — production systems I design, secure and maintain. Available for part-time collaboration and focused freelance work.
Linux server provisioning, hardening, monitoring and maintenance across VPS and on-prem — keeping uptime high and surprises low.
Dockerised services, virtualization on Proxmox, reverse proxies and automated workflows. Learning Kubernetes and infrastructure-as-code.
Honeypot deployment, threat detection and intrusion prevention with CrowdSec — plus hands-on ethical hacking and pentesting practice.
The homelab I run, right now
A self-managed hybrid environment across Proxmox and three VPS servers — where I run, break and harden real services.
secpro.sk — hybrid infrastructure
Self-hosted & maintainedCompute & virtualization
Proxmox host plus three VPS servers running Dockerised services behind a reverse proxy.
Security & detection
Cowrie honeypots for threat analysis and CrowdSec-driven automated detection across the fleet.
Networking & ops
VLAN segmentation, VPN access, backups and Grafana dashboards for visibility.
Tools I work with
Security & Pentesting
Infrastructure & DevOps
Programming & Scripting
Networking & Admin
Where I've worked
From front-line technical support to running secure infrastructure as a sysadmin.
Office 365 and domain migrations, DHCP troubleshooting, backup creation and L1/L2 support — keeping company systems secure and available.
Securing IT and OT (operational technology) environments — assessing risk, hardening systems and applying security controls across industrial and office networks. Worked with Claroty for OT asset visibility and monitoring, and carried out SOC work.
1st & 2nd level technical support and ticketing — prioritizing incoming issues, then reproducing customer-reported problems through manual testing and debugging to find root causes.
Communicated with stores with one goal: resolving problems as quickly and efficiently as possible. I genuinely enjoyed the problem solving — and Tesco's IT systems really appealed to me.
Set up a local email server, managed user permissions, installed Windows and hardware, and delivered IT project work in an educational environment.
Local server management, VLAN configuration, backups and hardware installation for the town's IT environment.
Background
Server management, optimization techniques and cybersecurity fundamentals.
Programming in Python, C, C#, Perl and Assembly. Local networking setup and .NET application development.
Languages
Let's build something solid.
Open to part-time roles and focused freelance projects in system administration, L1/L2 support and cybersecurity. The fastest way to reach me is email.
admin@secpro.sk