# Alexander Extim

> Alexander Extim — DevOps/SRE engineer and security researcher. Kubernetes, GitOps, cloud infrastructure, Linux, and technical notes from production.

Source: https://extim.su/


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    <img class="homepage__avatar" src="/images/avatar-default.svg" alt="Alexander Extim" width="200" height="200">
    <h1 class="text-get-big homepage__title">Hi! <span>I'm Alexander</span></h1>
    <p class="homepage__tagline">
      <a href="/about/">security · engineer · researcher</a>
    </p>
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        <a aria-label="Github" class="social-profiles__link" rel="noopener noreferrer" href="https://github.com/extimsu/" title="Github - extimsu">
          <i class="social-profiles__icon icon-github"></i>
          <span class="social-profiles__label">code</span>
          <span class="social-profiles__link-text">github.com/<strong>extimsu</strong></span>
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        <a aria-label="LinkedIn" class="social-profiles__link" rel="noopener noreferrer" href="https://www.linkedin.com/in/extim/" title="LinkedIn - extim">
          <i class="social-profiles__icon icon-linkedin -heartbeat"></i>
          <span class="social-profiles__label">linkedin</span>
          <span class="social-profiles__link-text">linkedin.com/<strong>in/extim</strong></span>
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      <li class="social-profiles__item">
        <a aria-label="Email" class="social-profiles__link js-mail" href="#" data-user="it" data-domain="extim.su" data-title="Email - {addr}" title="Email">
          <i class="social-profiles__icon icon-envelope"></i>
          <span class="social-profiles__label">email</span>
          <span class="social-profiles__link-text js-mail-text">it [at] extim.su</span>
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      <li class="social-profiles__item">
        <a aria-label="GPG Public Key" class="social-profiles__link" href="/gpg.asc" title="Download GPG Public Key">
          <i class="social-profiles__icon icon-key"></i>
          <span class="social-profiles__label">gpg</span>
          <span class="social-profiles__link-text">secure <strong>communication</strong></span>
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    <p class="homepage__bio-link"><a href="/about/">More about me →</a></p>
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  <section class="homepage__panel homepage__summary">
    <h2>Security, engineering and research</h2>
    <p>
      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.
    </p>
    <p>
      I work across <strong>AWS, GCP and Azure</strong>, and on-premises stacks with Proxmox, VMware and
      libvirt. Most of my tooling is written in <strong>Golang, Python and Bash</strong>. 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.
    </p>
    <p>
      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.
    </p>
    <p>
      This site is my personal home on the web. The <a href="/blog/">notes</a> cover Kubernetes, GitOps,
      Talos, Kargo, nginx ingress, Linux operations, secrets management, platform engineering, and lessons
      from production. The <a href="/about/">about page</a> lists experience and tooling in more detail.
      <a href="/photography/">Photography</a> 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 <a href="/llms.txt">/llms.txt</a>.
    </p>
    <h3>Topics on this site</h3>
    <ul>
      <li>Kubernetes upgrades, rollbacks, resource limits, and day-two operations</li>
      <li>GitOps with Argo CD and Kargo for progressive delivery</li>
      <li>Talos Linux, bare-metal and edge clusters, including Raspberry Pi setups</li>
      <li>Nginx ingress, TLS certificates, TCP routing, and reverse-proxy patterns</li>
      <li>Secrets in Kubernetes: CSI drivers, Vault, and safe configuration workflows</li>
      <li>Linux troubleshooting, networking, ACLs, and automation with Ansible and Terraform</li>
      <li>Platform engineering, observability, and practical SRE notes from the field</li>
    </ul>
    <p class="homepage__contact">
      Contact: <a class="js-mail" href="#" data-user="it" data-domain="extim.su"><span class="js-mail-text">it [at] extim.su</span></a> ·
      <a href="https://github.com/extimsu/" rel="noopener noreferrer">GitHub</a> ·
      <a href="https://www.linkedin.com/in/extim/" rel="noopener noreferrer">LinkedIn</a> ·
      <a href="/gpg.asc">GPG key</a>
    </p>
  </section>
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<div class="homepage__toolbar">
  <nav class="homepage-nav" aria-label="Site sections">
    <a class="homepage-nav__link" href="/blog/">My Notes</a>
    <a class="homepage-nav__link" href="/photography/">Photography</a>
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<section class="homepage-blog-wrapper">
  <h2 class="homepage-blog-wrapper__title">Latest Notes</h2>
  



  <ul class="ln ln-cards ln-slide">
    
    <li style="--i: 0">
      <a href="/blog/upgrading-kubernetes-with-emulated-version-✅/" class="ln-card">
        <h3 class="ln-title">Upgrading Kubernetes with emulated version ✅</h3>
        <time class="ln-date" datetime="2025-12-02">02 Dec 2025</time>
        
        <p class="ln-desc">Upgrading Kubernetes with emulated version </p>
        
      </a>
    </li>
    
    <li style="--i: 1">
      <a href="/blog/ingress-nginx-alternatives-🌝/" class="ln-card">
        <h3 class="ln-title">Ingress NGINX Alternatives 🌝</h3>
        <time class="ln-date" datetime="2025-11-29">29 Nov 2025</time>
        
        <p class="ln-desc">Ingress NGINX Alternatives </p>
        
      </a>
    </li>
    
    <li style="--i: 2">
      <a href="/blog/exposing-tcp-services-like-kafka-mongodb-and-clickhouse-using-nginx-ingress-controller-2026-guide-🔥/" class="ln-card">
        <h3 class="ln-title">Exposing tcp services like Kafka, MongoDB, and Clickhouse using Nginx Ingress Controller 2026 guide 🔥</h3>
        <time class="ln-date" datetime="2025-11-11">11 Nov 2025</time>
        
        <p class="ln-desc">Exposing tcp services like Kafka, MongoDB, and Clickhouse using Nginx Ingress Controller 2026 guide</p>
        
      </a>
    </li>
    
    <li style="--i: 3">
      <a href="/blog/access-control-listsacl-in-linux-🔒/" class="ln-card">
        <h3 class="ln-title">Access Control Lists(ACL) in Linux 🔒</h3>
        <time class="ln-date" datetime="2025-10-28">28 Oct 2025</time>
        
        <p class="ln-desc">Stop fighting chmod: Meet Linux ACLs (Access Control Lists)</p>
        
      </a>
    </li>
    
    <li style="--i: 4">
      <a href="/blog/kargo-the-new-promotion-orchestrator-for-argo-cd-🔥/" class="ln-card">
        <h3 class="ln-title">Kargo the New Promotion Orchestrator for Argo CD 🔥</h3>
        <time class="ln-date" datetime="2025-10-13">13 Oct 2025</time>
        
        <p class="ln-desc">Kargo the New Promotion Orchestrator for Argo CD</p>
        
      </a>
    </li>
    
    <li style="--i: 5">
      <a href="/blog/kubectl-cheat-sheet-📎/" class="ln-card">
        <h3 class="ln-title">Kubectl Cheat Sheet 📎</h3>
        <time class="ln-date" datetime="2025-09-30">30 Sep 2025</time>
        
        <p class="ln-desc">Kubectl Cheat Sheet</p>
        
      </a>
    </li>
    
    <li style="--i: 6">
      <a href="/blog/kubernetes-pod-level-resources-graduated-😈/" class="ln-card">
        <h3 class="ln-title">Kubernetes Pod Level Resources Graduated 😈</h3>
        <time class="ln-date" datetime="2025-09-26">26 Sep 2025</time>
        
        <p class="ln-desc">Helm or Kustomize, which one to use?</p>
        
      </a>
    </li>
    
    <li style="--i: 7">
      <a href="/blog/helm-🆚-kustomize/" class="ln-card">
        <h3 class="ln-title">Helm 🆚 Kustomize</h3>
        <time class="ln-date" datetime="2025-09-21">21 Sep 2025</time>
        
        <p class="ln-desc">Helm or Kustomize, which one to use?</p>
        
      </a>
    </li>
    
    <li style="--i: 8">
      <a href="/blog/talos-and-k8s-cluster-on-raspberry-pi-✨/" class="ln-card">
        <h3 class="ln-title">Talos and K8s cluster on Raspberry PI ✨</h3>
        <time class="ln-date" datetime="2025-09-09">09 Sep 2025</time>
        
        <p class="ln-desc">The most reliable ready-to-use K8s cluster on Raspberry PI</p>
        
      </a>
    </li>
    
  </ul>


</section>

