# Daan van Gorkum

> Senior Site Reliability Engineer specializing in Linux, Infrastructure as Code, Python, and Go.

I am a **Senior Site Reliability Engineer** based in Singapore with a focus on **Linux platforms**, **bare-metal automation**, and **global networking** (BGP, DNS, CDNs).

Over the past decade at **Cloudflare**, **Adyen**, and **Thales Cybersecurity**, I have engineered systems spanning the entire stack—from UEFI provisioning and bare-metal lifecycle management to distributed storage with [**CEPH**](https://ceph.io/), traffic engineering, and container orchestration with [**Kubernetes**](https://kubernetes.io/).

Outside of work, I operate my own autonomous system ([**AS209792**](https://bgp.tools/as/209792)), build open-source utilities in [**Python**](https://www.python.org/) and [**Go**](https://go.dev/), and volunteer with [**Repair Kopitiam**](https://repairkopitiam.sg/) diagnosing and fixing consumer electronics.

## Pages

- [Home & Engineering Profile](https://dj.vg/index.md): Career track record, projects, skills, and AS209792 infrastructure overview.
- [All Technical Articles](https://dj.vg/posts/index.md): Complete index of engineering writeups and security advisories.
- [Full Site Context (llms-full.txt)](https://dj.vg/llms-full.txt): Single-file Markdown bundle containing the full profile and all published articles.

## Articles

- [CVE-2026-109618 & CVE-2026-109619: Mitigating Critical PHP Session Upload Progress Use-After-Free Vulnerabilities Without Upgrading](https://dj.vg/posts/cve-2026-109618-cve-2026-109619-php-upload-progress-uaf-mitigation/index.md) (2026-10-21): Urgent request-level and web-server mitigations for CVE-2026-109618 and CVE-2026-109619 in PHP's RFC 1867 session upload progress handler (ext/session/session.c) using NGINX, Apache, HAProxy, ModSecurity, and OpenResty when you cannot immediately upgrade PHP.
- [Bridging a Cloud Condo Intercom to Home Assistant with Rust, SIP, and MQTT](https://dj.vg/posts/bridging-condo-intercom-to-home-assistant-rust-sip-mqtt/index.md) (2026-10-17): How I replaced a sluggish property-management app with a self-contained Rust daemon that speaks Firebase Cloud Messaging, SIP/TLS, H.264 RTP, and Home Assistant MQTT Auto-Discovery.
- [Fixing Entra ID / Azure AD AADSTS75011 on Ceph Dashboard SAML](https://dj.vg/posts/fixing-ceph-dashboard-saml-aadsts75011/index.md) (2026-10-17): How to resolve Microsoft Entra ID error AADSTS75011 when authenticating to the Ceph Dashboard with FIDO2 security keys or MFA by disabling requestedAuthnContext in the Ceph monitor store.
- [Why I Built BCRSTracking: Telemetry for Singapore's Bottle Return Scheme](https://dj.vg/posts/why-i-built-bcrs-tracking/index.md) (2026-09-12): Tired of walking to full reverse vending machines with bags of recyclables, I built a Go and ClickHouse service to monitor Singapore's nationwide container return scheme.
- [The 'Datacenter at Home': A Multi-Homed BGP & WireGuard Mesh Architecture](https://dj.vg/posts/datacenter-at-home-bgp-wireguard-saltstack/index.md) (2026-01-31): How to apply hyperscale datacenter design principles to a home network using eBGP, WireGuard, and SaltStack orchestration.
- [Easy and free Dynamic DNS](https://dj.vg/posts/free-dynamic-dns/index.md) (2025-10-04): A lightweight, stateless Dynamic DNS service built with FastAPI.
- [Timelapse system: a start](https://dj.vg/posts/timelapse-system-a-start/index.md) (2022-01-25): How I built a system to take a photo every minute, eventually storing over 750k photos and 6.2TB of data.

## Projects

- [XYZ.FRL](https://l.dj.vg/xyz.frl): Free stateless Dynamic DNS service. No account required, privacy-first, simple API.
- [IMGDumper.nl](https://l.dj.vg/imgd): Free and fast image hosting platform with direct uploads, operating continuously since 2007.
- [BCRSTracking](https://l.dj.vg/bcrs): Cloud-native Go tracking service monitoring reverse vending machine availability, status, and bin capacity across Singapore's Beverage Container Return Scheme.
- [KovanWellspring.SG](https://l.dj.vg/kw): Tracking platform for the Kovan Wellspring BTO development with real-time visual updates and timelapses.
- [KopiTool](https://gitlab.sin.djvg.net/kopitool/kopitool): Repair tracking tool for Repair Kopitiam, a volunteering organization dedicated to reducing e-waste.
- [netbox-more-metrics](https://github.com/TheDJVG/netbox-more-metrics): Netbox Plugin exporting custom Prometheus metrics from NetBox data using Python.
- [vault-backup](https://github.com/TheDJVG/vault-backup): Go CLI to backup HashiCorp Vault raft snapshots directly to AWS S3 or compatible endpoints.
- [netbox-field-permissions](https://github.com/TheDJVG/netbox-field-permissions): Plugin to limit user/group access to change specific object field values in NetBox.