2022-06startLinux System Administrator @ Özgür Yazılım A.Ş. (Remote)
2022-06infoDesigned, 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.
2022-06infoInstalled, maintained and optimized Red Hat and Debian based Linux servers for clients across various industries and scales.
2022-06infoImplemented 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.
2022-06infoDeployed Keycloak in high availability and integrated SSO with GitLab, Zabbix, Nextcloud and Rocket.Chat; provided centralized identity management with OpenLDAP.
2022-06infoBuilt a HashiCorp Vault cluster backed by Consul; implemented secret injection into Kubernetes pods with Vault Agent and the Zabbix–Vault integration.
2022-06infoDesigned and managed virtualization platforms based on KVM/QEMU, VMware and Proxmox, including resource planning and high-availability configurations.
2022-06infoProvided load balancing and high availability with Keepalived + HAProxy clusters and Envoy proxy.
2022-06infoAutomated maintenance, monitoring and deployment processes with Bash and Python, and built custom tools to reduce manual operations.
2022-06infoBuilt 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.
2022-06infoSet 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.
2022-06infoMigrated 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.
2022-06infoDeployed and managed Kafka and RabbitMQ clusters, and built a disaster recovery setup for Kafka based on cross-cluster replication with MirrorMaker.
2022-06infoInstalled and maintained management and monitoring tools such as Zabbix, Graylog/Rsyslog, Bacula and GitLab.
2021-11startPart-Time Technical Staff @ Ege University (İzmir)
2021-11infoDiagnosed and repaired computer hardware and software issues and provided end-user technical support.
2021-11infoInstalled and configured network devices (routers, switches, access points, firewalls) and built and maintained LAN infrastructure.
2021-11infoInstalled and managed Windows Server 2012 R2 and 2016 environments, thin client and terminal systems.