Last weekend, we delivered a new event to the CTF community: OmniCTF 2026 Quals.
I was the only person responsible for the infrastructure and all challenge pods. It was a difficult job, especially after AWS restricted our account one day before the CTF.
I also had my Cambridge C2 exam on the last day of the CTF. Managing the exam and the event at the same time made the weekend even more difficult. 😭
We had to move the full setup to Google Cloud as fast as possible. The USD 300 free-trial credit was useful, but it did not cover the full cost. We had to pay approximately EUR 110 out of our own pockets. 😭
My work during the event
I managed the infrastructure, the challenge instances, and the files that the instancers used. I also authored or helped to author many challenges.
I had more time to work on challenges this year. However, the final challenge set was not as polished as I wanted. I hope that we can use a better development and testing process next year.
The infrastructure load
The first dashboard shows the number of concurrent instances for each challenge. The workload changed substantially during the event. At the busiest point, the platform ran close to 300 concurrent challenge instances.
The full Grafana dashboard gives more context. It shows the average concurrent instances, instance starts, node CPU usage, and node memory usage.
Some challenges had a much higher load than others. For example, ganzir
reached 52 concurrent instances and had 574 instance starts. staywild
reached 46 concurrent instances and had 355 starts. The CPU and memory graphs
also show the short load spikes that occurred near the end of the event.
The last-minute cloud migration
AWS restricted our account one day before the CTF. AWS restored access about four hours before the event and then restricted the account again.
This forced us to prepare the infrastructure quickly on Google Cloud. The fast migration caused many of the infrastructure problems that we saw during the CTF. I do not plan to use AWS for this event again.
The AWS activity was not an attack. I gave a friend access so that they could help me upload and organize the challenge files. The instancers required these files to start the challenge environments.
The platform
This year, we used rCTF v2. It is a CTF platform created by es3n1n and the OtterSec Team. It is the best CTF platform that I have used.
Special thanks to es3n1n for listening to my AWS problems.
I will not publish our configuration files. For a detailed example of a good CTF infrastructure setup, read es3n1n’s SekaiCTF 2026 infrastructure write-up.
Sponsors and thanks
Many sponsors helped us make this event possible. Special thanks to Orange and OtterSec for their financial support for the finals. Orange asked to remain anonymous during the qualification stage.
Thank you to everyone who played, helped, or supported OmniCTF 2026 Quals. The event had rough edges, but it gave us useful lessons for the next edition.