{
  patrick = {
    role     = "Platform & security engineer";
    at       = "SLTN, Azure Expert MSP";
    builds   = [ "identity" "delivery" "recovery" "AI infrastructure" ];
    writes   = [ "Terraform" "Bicep" "PowerShell" "Python" "Rust" "Nix" ];
    believes = "every change reviewed, nobody over-privileged";
    home     = "https://patrick.kappen.io";
  };
}

I build the platforms other people deploy to, and the guard rails around them. Most of my work sits where infrastructure, identity and automation meet, and lately a good part of it is about letting AI agents in without handing them the keys.

• If it's not in Git, it doesn't exist. Portal clicks are drift with extra steps.
• A backup you haven't restored is a rumour. Recovery gets tested, or it isn't there.
• Standing admin access is a bug, not a convenience. Rights are granted just in time and expire on their own.
• AI agents get the intern treatment. A sandbox, a reviewer, and no production keys. I've watched an automated PR merge a feature, revert it, and still announce it in the release notes.
• Boring in production, interesting in design. The exciting part should be the pull request, not the incident.

At SLTN I own the platform code that our cloud teams and customer tenants run on, and I work with our CISO to turn security policy into automation instead of documents.

That currently means moving the whole organisation from Azure DevOps to GitHub and swapping every stored pipeline secret for OIDC on the way. Customer access runs through GDAP, Azure Lighthouse and PIM, all in Terraform, so changing who can do what is a pull request like any other. Around that sit automated landing zones and disaster recovery drills that fail over a full Azure Site Recovery plan, prove the machines come back, and always clean up after themselves.

Open models as coding agents. I pick, benchmark and tune open-weight models on vLLM, with my own suite for tool calling, long agent tasks, long context and many agents at once. Models are chosen on measured numbers for the actual workload, not on a leaderboard.

Agents with boundaries. Sandboxed execution, scoped credentials, human-approved Git promotion and agent setups declared in Nix, so every one of them can be rebuilt and audited.

A homelab run like production. Proxmox, Talos Kubernetes, GitOps, OpenTofu and Ansible; TrueNAS and Proxmox Backup Server with 3-2-1 backups on 10 Gbit; Prometheus, Grafana and Loki watching it all. My machines are a NixOS fleet with signed commits, built so that a compromised GitHub account can't push code onto them.

Graft turns a few lines of TOML into Podman Quadlet containers built from the Nix store. Describe what the container needs; Nix builds the rest.

• Studying for GitHub Actions and AI-103
• Building a blog on patrick.kappen.io

Last changed Oct 2026.

• Two GitHub accounts, one machine, zero switching

graft · TOML-driven Podman Quadlet containers, built from the Nix store.

• 🐛 Make rootless notify protocol fixture runnable · Aug 2026 · +22 −22
  Install the protocol fixture's user services through systemd.user.services, avoiding the generated /etc/systemd/user collision.
• 🐛 Retain user Quadlet readiness through conmon handoff · Aug 2026 · +257 −30
  Fixes the rootless Quadlet notify-attribution race that blocked the v0.4.0-alpha.1 release candidate.
• 🐛 Keep relaxed user manifests loadable · Aug 2026 · +366 −76
  Keeps relaxed user manifest publication readable by the installed worker and prevents tolerated default ACLs from making newly created Graft directories unusable.
• 🐛 Finalize publication base-directory policy · Aug 2026 · +503 −141
  Finalizes secure user publication directory handling while supporting NAS and permission-less filesystems through an explicit opt-in compatibility mode.
• ✨ Install worker sockets and services · Aug 2026 · +277 −14
  Installs the documented system and user Graft worker services and sockets with fixed, Nix-expanded manifest paths, target/manager/UID policy, producer identity, and local-only…
• ✨ Publish Home Manager user manifests atomically · Aug 2026 · +260 −22
  Implements Home Manager-only immutable manifest/endpoint publication through $XDG_CONFIG_HOME/graft/current, using its own validated user activation lock and atomic pointer…

• Cloud: Azure · IBM Cloud · AWS · Proxmox
• IaC & delivery: Terraform/OpenTofu · Bicep · GitHub Actions · Azure DevOps · Ansible · Nix
• Identity & security: Entra ID · PIM/JIT · GDAP · Lighthouse · OIDC · Key Vault · SOPS
• Containers: Kubernetes · Talos · Podman/Quadlet · Docker · Helm
• Code: PowerShell · Python · TypeScript · Rust · Bash
• AI: vLLM · Ollama · llama.cpp · LiteLLM · LangGraph · Langfuse · Phoenix

• Certified: AZ-900 · AZ-104 · AZ-400
• Working towards: GitHub Actions · GitHub Administration · AI-103 (Azure AI Apps and Agents)