Berkay Güçlü (Berkay Guclu) · Linux System Administrator

berkay@opensuse:~> whoami

Berkay Güçlü

Linux System Administrator

Ankara, Turkey

berkay@opensuse:~> cat about.txt

System Administrator specializing in Linux and Kubernetes-based infrastructures, with a strong focus on automation and observability. Experienced in designing and managing reliable, scalable and sustainable systems for customer environments of every scale. Continuously improving my technical skills by closely following industry developments.

berkay@opensuse:~> cat contact.yaml

email: iletisim@berkayguclu.com

linkedin: linkedin.com/in/berkay-guclu

blog: Personal Blog

berkay@opensuse:~> journalctl -u career --no-pager # experience

[June 2022 – Present]

Linux System Administrator @ Özgür Yazılım A.Ş., Remote

Designed, deployed and managed highly available and scalable Kubernetes (RKE2, OpenShift, Talos Linux) cluster architectures; deployed and operated services such as GitLab, Jenkins, SonarQube, Nexus, Keycloak, Rocket.Chat, Jitsi, Nextcloud and OpenSearch on Rancher, and configured Longhorn backups.
Installed, maintained and optimized Red Hat and Debian based Linux servers for clients across various industries and scales.
Implemented server security, user authorization and system update policies; set up intrusion detection with Wazuh and OSSEC and vulnerability scanning with Nessus, and defined server hardening and firewall standards.
Deployed Keycloak in high availability and integrated SSO with GitLab, Zabbix, Nextcloud and Rocket.Chat; provided centralized identity management with OpenLDAP.
Built a HashiCorp Vault cluster backed by Consul; implemented secret injection into Kubernetes pods with Vault Agent and the Zabbix–Vault integration.
Designed and managed virtualization platforms based on KVM/QEMU, VMware and Proxmox, including resource planning and high-availability configurations.
Provided load balancing and high availability with Keepalived + HAProxy clusters and Envoy proxy.
Automated maintenance, monitoring and deployment processes with Bash and Python, and built custom tools to reduce manual operations.
Built fully automated CI/CD pipelines integrating Jenkins, SonarQube and Nexus, using Jenkins Configuration as Code and containerized jobs, and added code quality and security analysis with Fortify SCA and Dependency-Track.
Set up PostgreSQL automatic failover with Patroni and Consul and disaster recovery with repmgr and Barman; managed Valkey Sentinel, Redis Cluster and MongoDB replica sets, and ran backup and migration work for databases including MySQL.
Migrated from Elasticsearch to OpenSearch with cross-cluster replication (CCR) for disaster recovery; upgraded Graylog clusters from 2.x to 7.x and built log collection with Logstash, Nxlog and Graylog Sidecar.
Deployed and managed Kafka and RabbitMQ clusters, and built a disaster recovery setup for Kafka based on cross-cluster replication with MirrorMaker.
Installed and maintained management and monitoring tools such as Zabbix, Graylog/Rsyslog, Bacula and GitLab.

[November 2021 – June 2022]

Part-Time Technical Staff @ Ege University, İzmir

Diagnosed and repaired computer hardware and software issues and provided end-user technical support.
Installed and configured network devices (routers, switches, access points, firewalls) and built and maintained LAN infrastructure.
Installed and managed Windows Server 2012 R2 and 2016 environments, thin client and terminal systems.

berkay@opensuse:~> ls ~/projects/homelab # projects

Personal infrastructure (homelab)

Infrastructure I built from scratch and keep evolving on a single Proxmox VE host to run my own services. This site runs on it too.

3-node RKE2 Kubernetes cluster on Proxmox VE 9, with kube-vip API VIP, Longhorn distributed storage and Traefik ingress.
SNI-based routing with HAProxy; automatic certificates with cert-manager and Let's Encrypt DNS-01.
Self-hosted mail server with Stalwart (SPF, DKIM, DMARC, reverse DNS) and webmail.
Metrics with VictoriaMetrics, node-exporter and Grafana; monitoring and alerts with Uptime Kuma and ntfy; image update tracking with Diun.
Local LLM server with llama.cpp and Open WebUI; Python automation that summarizes daily system reports.
DNS-over-TLS with AdGuard Home and encrypted backups with restic.

berkay@opensuse:~> kubectl get skills -o wide

NAME	STATUS	TOOLS
linux	Ready	Debian, Red Hat / Rocky, Ubuntu, openSUSE, Arch, systemd, SELinux, firewalld
containers	Ready	Docker, Kubernetes, RKE2, OpenShift, Rancher, Talos, k3s, kubeadm, Helm, Longhorn
virtualization	Ready	KVM/QEMU, Proxmox VE, VMware, VirtualBox
automation-&-ci/cd	Ready	Bash, Python, Ansible, Jenkins, GitLab, SonarQube, Nexus, Dependency-Track
monitoring-&-logging	Ready	Zabbix, Grafana, Graylog, Rsyslog, VictoriaMetrics, Logstash, Kibana, OpenSearch Dashboards, Nagios XI, Sentry
identity-&-security	Ready	Keycloak, HashiCorp Vault, OpenLDAP, Wazuh, OSSEC, Nessus
databases	Ready	PostgreSQL, MySQL, MongoDB, Patroni, repmgr
search,-cache-&-messaging	Ready	OpenSearch, Elasticsearch, Redis, Valkey, RabbitMQ, Kafka
web-&-application-servers	Ready	Apache, Nginx, PHP-FPM, Tomcat, WildFly
backup-&-storage	Ready	Bacula, Barman, MinIO
networking	Ready	TCP/IP, DNS, PowerDNS, HAProxy, Keepalived, Envoy, WireGuard, OpenVPN, Let's Encrypt

berkay@opensuse:~> history | grep training # teaching

Özgür Yazılım A.Ş.

Linux System Administration 101-102-103-104
Kubernetes 101
Jenkins Workshop
Ansible Workshop

Mustafa Akgül Free Software Camps [2023 – 2025]

Log Management and Analysis with Graylog
GNU/Linux System Administration (Level 1)
Server and Service Monitoring with Zabbix
Kubernetes and Container Technologies

berkay@opensuse:~> cat education.yaml

- degree: "Management Information Systems (Distance Education)"
school: "Ankara University"
years: "2024 – Present"

- degree: "Computer Programming"
school: "Ege University"
years: "2020 – 2022"

berkay@opensuse:~> locale -a

Turkish — native

English — B2

berkay@opensuse:~>

Web designs were made with the help of a local LLM.