Automating CTF Platform deployment: How to host a large scale CTF in the cloud

Running a large scale CTF event is no small feat. Doing so with dynamic provisioning of challenge instances for hundreds or thousands of participants requires significant infrastructure planning and automation.

In this talk, Mikkel will dig into how we automated the deployment and management of the infrastructure needed to run BrunnerCTF 2025, an international Capture The Flag event, which had more than 1100 teams on the scoreboard.

Programme:
17:00 - 17:15 Welcome and settle in
17:15 - 17:45 Part 1
17:45 - 18:15 Food and friendmaking
18:15 - 18:59 Part 2
19:00 - Bye :-)

Some of the topics Mikkel will cover include:

• Infrastructure as Code (IaC) & GitOps: Streamlining the platform and challenge deployment.
• Core Tooling: Using Terraform for Kubernetes cluster provisioning in Hetzner Cloud.
• Custom Automation: Leveraging custom JSON schemas and Python scripts to generate Kubernetes deployment files.
• Challenge instancing: Dynamic on-demand challenge instance provisioning.
• Interesting stats and metrics from BrunnerCTF 2025.

Mikkel will also share the challenges we faced and the hard-won lessons learned, such as:

• Deploying a Kubernetes cluster in Hetzner
• Running a clustered MariaDB setup
• How we didn't survive the first 20 minutes of the CTF

And much more.

You will therefore gain practical insights into running a real-world, large-scale CTF in production, maximizing automation and cloud technologies.

Tonight's speaker:
Mikkel Albrechtsen is a regular attendee in Cloud Club and a jack of many trades. He is a software engineering student, a student worker at several companies and an instructor at SDU. He is a youtuber and a photographer who shares great photos on Instagram.

Want to join?
Hey - it is free. You will be among a friendly crowd. There is food.
Please sign up no later than the day before at noon. But why wait?

Venue:
At Syddansk Universitet. Room TBA