René Zingerle
DevSecOps & Kubernetes Engineer (Freelance)
Experience
DevSecOps & Kubernetes Engineer (Freelance)
mgm technology partners GmbH
Development of a Custom Jenkins Shared Library (Groovy)
Integration of security checks in CI/CD pipeline (Shift-Left Approach)
Automated vulnerability scanning and remediation workflows
GitOps-based deployments with ArgoCD
Semantic versioning automation with Git integration
Container lifecycle management (Build/Scan/Tag/Push)
ArgoCD webhook integration for event-driven deployments
Complete cluster automation with Ansible
Bare-metal Kubernetes installation from scratch
High-availability control plane setup
Unified deployment system for multi-application orchestration
Configuration management according to NIST SP 800-128
Host security: Linux hardening, SELinux/AppArmor
Network security: NetworkPolicies, micro-segmentation
Application security: RBAC, Pod Security Standards
Data security: Encryption at rest and in transit
Defense-in-depth principles
Certificate management with cert-manager
Secrets management with External Secrets Operator connected to Vault
Infrastructure monitoring with Checkmk
Prometheus/Grafana monitoring stack
Security event detection and logging
Automated health checks and incident response procedures
MetalLB load balancing for bare-metal
Nginx ingress controller with SSL passthrough
NetworkPolicies for security zones
Rook-Ceph distributed storage, CNI configuration (Weave Net)
Container & orchestration: Kubernetes (bare-metal), Docker, Helm
CI/CD & GitOps: Jenkins (Custom Shared Library), ArgoCD, Groovy
Automation: Ansible, Bash, Python
Security: nftables, RBAC, NetworkPolicies, cert-manager, Vault, Sealed Secrets
Monitoring: Checkmk, Prometheus, Grafana
Storage & networking: Rook-Ceph, MetalLB, Nginx Ingress, Calico
Collaboration: Jira, Confluence
OS: Debian, Ubuntu
Founder & Managing Director | DevSecOps Engineer
Rothirsch Tech GmbH
Built and run an on-premise data center in Tyrol, Austria with bare-metal servers, Kubernetes clusters, CI/CD pipelines
Handled strategy, finances, customer relations, compliance and IT security governance
Jenkins Shared Library: Groovy functions for CI/CD automation, semantic versioning, Docker lifecycle, ArgoCD integration
GitOps architecture: ArgoCD App-of-Apps pattern, Kustomize overlays, automated ApplicationSet generation
Security integration: Policy-as-Code, automated security testing in CI/CD, container image scanning
Ansible framework: Production-grade custom roles for cluster lifecycle, database, network, IAM, mail
Puppet framework: Configuration management compliant with NIST SP 800-128, 5-layer governance structure
Kubernetes cluster from scratch: bare-metal multi-node setup, HA control plane, Rook-Ceph storage, MetalLB load balancing
Security: RBAC, NetworkPolicies, Pod Security Standards, TLS/mTLS, secrets management (Vault)
Production services: Hosting platforms (insa.tirol), multi-tenant customer deployments
System security: Linux hardening, kernel tuning, patch management
Network infrastructure: nftables/iptables, Nginx/Apache, Strongswan VPN, Bind9 DNS
Identity & Access Management: OpenLDAP multi-master replication, Keycloak SSO, PKI & certificate management, MFA
Database & high-availability: MariaDB Galera multi-master clustering, MaxScale proxy, automated backup/restore workflows, zero-downtime maintenance
Custom containerized services: WordPress, mail (Postfix/Dovecot/Amavis), IAM (OpenLDAP/Keycloak), monitoring
Multi-stage builds, security hardening, multi-architecture support (AMD64, ARM, ARM64)
Monitoring & observability: Prometheus, Grafana, ELK Stack (Filebeat, Metricbeat), Icinga2, custom health check endpoints, security event detection
API-driven & event-driven automation: n8n workflow automation, GitLab API, ArgoCD API, Kubernetes API, webhooks
Container & orchestration: Kubernetes (bare-metal), Docker, Helm, Kustomize
CI/CD & GitOps: Jenkins (Custom Shared Library), ArgoCD, GitLab CI, n8n
Automation: Ansible, Puppet, Terraform, Bash, Python, Groovy
Security: nftables, Strongswan VPN, TLS/mTLS, HashiCorp Vault + External Secrets Operator
Monitoring: Prometheus, Grafana, ELK Stack, Icinga2
Database: MariaDB Galera, MaxScale
Storage & networking: Rook-Ceph, MetalLB, Nginx, Bind9 DNS
IAM: OpenLDAP, Keycloak, cert-manager, PKI
Mail: Postfix, Dovecot, Amavis, SpamAssassin, ClamAV, OpenDMARC, OpenDKIM
AI & workflow automation: Claude Code, n8n with LLM integration
OS: Debian, Ubuntu
Linux System Administrator & Automation Engineer
GMO Mechatronik GmbH
Built secure server infrastructure using open-source technologies (FLOSS)
Implemented VPN (Strongswan) and firewall configuration (iptables)
Managed network services: DNS (Bind9), DHCP, NTP, mail (Postfix with spam filtering)
Deployed Samba as Active Directory Domain Controller for centralized authentication and SSO
Performed system hardening, security monitoring, log analysis, and patch management
Automated routine tasks and workflows with custom Bash and Python scripts
Networking: Strongswan VPN, iptables, Bind9 DNS, DHCP, NTP
Mail: Postfix, SpamAssassin
Directory Services: Samba AD DC, LDAP
Scripting: Bash, Python
OS: Debian, Ubuntu, RHEL
IT Technician Apprenticeship & First Level Support
Heinzle GmbH
- Completed an IT technician apprenticeship
- Provided first level support for internet and IT services
Cabinetmaker Apprenticeship, Journeyman & CNC Developer
GMO Mechatronik GmbH
Completed a cabinetmaker apprenticeship and journeyman qualification
Built a CNC milling machine: partner did mechanical construction, I did electronics and software (LinuxCNC)
Developed custom software for CNC code replication using Bash and awk
Automated manufacturing processes with user-friendly tooling
CNC & Automation: LinuxCNC
Scripting: Bash, awk
OS: Debian
Industries Experience
See where this freelancer has spent most of their professional time. Longer bars indicate deeper hands-on experience, while shorter ones reflect targeted or project-based work.
Experienced in Manufacturing (14 years) and Information Technology (12.5 years).
Business Areas Experience
The graph below provides a cumulative view of the freelancer's experience across multiple business areas, calculated from completed and active engagements. It highlights the areas where the freelancer has most frequently contributed to planning, execution, and delivery of business outcomes.
Experienced in Information Technology (23 years), Operations (9.5 years), Strategy (9.5 years), Product Development (9 years), Production (9 years), and Customer Service (3 years).
Summary
Full-time freelance DevSecOps Engineer with 15+ years in IT and 10+ years building my own company, Rothirsch Tech GmbH. I run a self-built on-premise data center in Tyrol, Austria, using Kubernetes to provide fully automated web services for regional customers. CISSP-certified security professional combining hands-on infrastructure expertise with CI/CD automation, Infrastructure-as-Code, and security-first design.
Skills
- On-premise Infrastructure
- Automation & Ci/cd (Jenkins, Gitlab Ci, Argocd)
- Infrastructure-as-code (Ansible, Python, Bash)
- Container Orchestration (Kubernetes, Docker)
- Security-first Architecture (Cissp)
Languages
Education
Heinzle GmbH
IT technician apprenticeship · Austria
Tischlerei Roberto Zingerle
Cabinetmaker apprenticeship · Austria
Certifications & licenses
CISSP – Certified Information Systems Security Professional
ISC²
SSCP – Systems Security Certified Practitioner
ISC²
Profile
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