Systems & Infrastructure Engineer | Network & DevOps

• Location: Prague, Czech Republic
• Contact: contact@garoshi.eu | [GitHub / LinkedIn / Web]
• Focus: Enterprise Networking, Linux Systems Engineering, Virtualization, High Availability & Cloud

Professional profile

Infrastructure and systems engineer with 6+ years of experience designing, operating and automating enterprise networks, virtualization clusters and highly available Linux systems. Background in regulated healthcare, public administration, fintech and 24/7 web hosting. Specialized in L2/L3 network architecture, Zero Trust and NIS2-compliant segmentation, Proxmox/VMware virtualization with distributed storage (Ceph), and automation with Bash, Python, Ansible and Terraform.

Work experience

Healthcare (Healthcare holding / Network of polyclinics) — IT Infrastructure Specialist / DevOps & Network Engineer

03/2026 – Present | Full-time / Contractor

• Architecture, modernization and operation of the IT infrastructure of a healthcare group spanning the headquarters, 7 polyclinics/branches and an external commercial data center (Tier III).
• Designed and rolled out a unified L2/L3 addressing plan and standardized segmentation across all sites, built on Zero Trust principles and compliant with the NIS2 directive / Czech Cybersecurity Act (ZKB).
• Deployment and management of Fortinet FortiGate enterprise firewalls (HA clusters, FortiManager) and L2/L3 switches, prepared for dynamic VLAN assignment via 802.1X (RADIUS).
• Strict network isolation of medical devices and systems (IoMT – PACS/X-ray/ultrasound), payment terminals, VoIP, CCTV and facility management.
• Architecture and sizing of the migration from VMware ESXi to a highly available 4-node Proxmox VE cluster with Ceph distributed storage (NVMe/SAS).
• Introduced NetBox IPAM as the Single Source of Truth for IP ranges and network topology, integrated with Zabbix and LibreNMS monitoring.
• Tech stack: Fortinet (FortiGate 200F/80F/40F, FortiManager), Ubiquiti UniFi, HPE Aruba, MikroTik, Proxmox VE, Ceph, VMware ESXi, NetBox IPAM, Zabbix, LibreNMS, Linux (Debian, Rocky Linux, Ubuntu), Windows Server, 802.1X, RADIUS, VLAN/VXLAN, Zero Trust, NIS2, WireGuard, IPsec.

Web hosting & Cloud provider — Linux Administrator / Hosting Engineer

11/2025 – 03/2026 | Contractor

• 24/7 operation and management of the hosting infrastructure, focused on server systems, virtualization and network services.
• Migration and deployment of web applications, SSL/TLS certificate automation, reverse proxy configuration, DNS and mail server management.
• Operation of production container environments (Docker, Kubernetes) and ensuring high availability of services.
• L2/L3 incident resolution, performance tuning and end-to-end monitoring in Zabbix.
• Tech stack: Linux (Rocky Linux, Debian, Ubuntu), Kubernetes, Docker, Proxmox VE, MikroTik, pfSense/OPNsense, Ubiquiti, NetBox, Grafana, Ansible, PostgreSQL, MySQL/MSSQL, Zabbix, WireGuard, OpenVPN.

IT Consulting & Software development — Linux Administrator / Network Engineer

11/2024 – 11/2025 | Contractor (16/7 on-call)

• Operation and management of hybrid IT infrastructure and client environments at L2 and L3.
• Management of network devices, VLAN routing, VPNs and firewall policies across a range of hardware platforms.
• Server management automation with Ansible, maintenance of network storage (TrueNAS, Synology) and backup systems (Bareos).
• Tech stack: MikroTik, FortiGate, Ubiquiti, Omada, VMware, Proxmox, AWS, Docker, Zabbix, GitLab, Grafana, Ansible, TrueNAS, Synology, Bareos, WireGuard, OpenVPN.

Fintech / Non-bank financial sector — Application Administrator

06/2024 – 11/2024 | Full-time

• Operation of an in-house production financial platform running in AWS on Kubernetes and EC2 virtual machines.
• Building and maintaining deployment pipelines (CI/CD), infrastructure as code (IaC) and telemetry.
• Tech stack: AWS, GCP, Kubernetes, Docker, Terraform, Helm, GitLab CI/CD, MongoDB, Grafana, Prometheus, Zabbix.

Digital agency / Enterprise development — Linux Administrator

01/2022 – 05/2024 | Full-time (24/7 and 8/5 on-call)

• Management of internal and client production infrastructure and high-traffic web applications.
• Automated provisioning and configuration of server systems with Ansible and Foreman.
• System health monitoring and outage resolution with Nagios, Prometheus and Grafana.
• Tech stack: Linux (CentOS, Rocky Linux, Ubuntu), Ansible, Foreman, Nagios, Docker, Azure, Kubernetes, HAProxy, MongoDB, Grafana, Prometheus.

State-owned enterprise (Transport infrastructure) — Systems Administrator

08/2020 – 12/2021 | Full-time

• Infrastructure and systems support for critical nationwide transport projects with high load and transaction volume.
• Management of a fleet of ~200 Linux (Debian) servers, declaratively managed with Puppet.
• Operation and orchestration of containerized microservices in Docker and Kubernetes on VMware vCloud.
• Tech stack: Debian, Puppet, Kubernetes, Docker, VMware vCloud, FortiGate, MikroTik, UniFi, PRTG, Git.

Earlier projects and community work

• Local ISP (2018): Modernization of the main transmission node, custom server builds, virtualization (Proxmox/ESXi) and routing configuration.
• IT outsourcing for SMBs (2018): IT infrastructure modernization, deployment of MikroTik, Synology, Microsoft 365, UniFi.
• Cultural festivals and media events (2015 – present): Design and build of temporary on-site network infrastructure, central storage for media content and on-site technical support.

Technical skills

Education and certifications

• Education: Secondary technical school of telecommunications and IT (completed with Maturita / high-school diploma)
• Certifications and courses:
• Cisco IT Essentials
• Cisco CCNA (curriculum completed)
• MikroTik MTCNA
• Ubiquiti UNP (UniFi Network Professional)

Languages

• Czech: Native speaker
• English: Professional working proficiency (B2 / technical documentation and communication)