Alexander Extim

Hi! I'm Alexander

security · engineer · researcher

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Security, engineering and research

I'm Alexander Extim, a DevOps and Site Reliability Engineer with more than eighteen years in IT. I design, build and operate infrastructure that keeps applications fast, secure and dependable. My work spans cloud platforms, bare-metal clusters, container orchestration, continuous delivery, observability, and security automation so teams can ship with confidence.

I work across AWS, GCP and Azure, and on-premises stacks with Proxmox, VMware and libvirt. Most of my tooling is written in Golang, Python and Bash. Day to day I use Kubernetes, Docker, Terraform, Helm, ArgoCD, Ansible, Vault, GitLab CI/CD and Jenkins, with Prometheus, Grafana and the ELK stack for monitoring and incident response.

Networking, identity, and hardening are part of the same job: DNS and VPNs, load balancers, OSPF and VPC design, HashiCorp Vault, Keycloak, Trivy, SonarQube, and secure configuration practices. I have run production systems on Linux and Windows Server and supported PostgreSQL, MySQL, MongoDB, Redis, and ClickHouse in real deployments.

This site is my personal home on the web. The notes cover Kubernetes, GitOps, Talos, Kargo, nginx ingress, Linux operations, secrets management, platform engineering, and lessons from production. The about page lists experience and tooling in more detail. Photography is a separate collection of places in Montenegro and beyond. For machines and agents, a Markdown copy of each page is linked in the document head; the site index for LLMs lives at /llms.txt.

Topics on this site

  • Kubernetes upgrades, rollbacks, resource limits, and day-two operations
  • GitOps with Argo CD and Kargo for progressive delivery
  • Talos Linux, bare-metal and edge clusters, including Raspberry Pi setups
  • Nginx ingress, TLS certificates, TCP routing, and reverse-proxy patterns
  • Secrets in Kubernetes: CSI drivers, Vault, and safe configuration workflows
  • Linux troubleshooting, networking, ACLs, and automation with Ansible and Terraform
  • Platform engineering, observability, and practical SRE notes from the field

Contact: it@extim.su · GitHub · LinkedIn · GPG key

Latest Notes