About

Hi, I’m Sebastian. I break into things for a living, carefully and with permission. These days that mostly means cloud and Kubernetes.

I’m a senior security analyst in the cloud security team at ERNW in Heidelberg. I’ve lost count of the cloud accounts and container platforms I’ve reviewed by now: AWS, Azure, Google Cloud, Alibaba Cloud, IBM Cloud, OpenStack and SAP Converged Cloud, Cloud Foundry, and pretty much every Kubernetes flavour out there (EKS, AKS, GKE, OpenShift, Rancher, Gardener, Kubermatic, Kubernikus). Several of those projects were for DAX 10 companies. The work I enjoy most is scenario-based red teaming against cloud and container platforms, and I’ve had the chance to lead a few of those.

I use AI agents a lot, mainly to automate the boring parts of an assessment. Collecting, sorting, re-checking: if a machine can do it reliably, it should, so I can spend my time on the findings that actually need someone to think.

Together with my colleague Sven Nobis I teach Offensive Kubernetes Security 101, at TROOPERS and as an open training with HM Training Solutions.

How I got here #

I studied at TU Darmstadt: a B.Sc. in Computer Science, then an M.Sc. in IT Security. During my master’s I did research on privacy for the Internet of Things, which turned into a couple of papers and a poster at IEEE and ACM venues.

Before ERNW I was a pentester at Context Information Security. Before that came research jobs at Fraunhofer SIT and AGT International, an internship as a software developer at TÜV Rheinland in Taipei, and web development at Kleewald in Frankfurt. The full list is in my resume.

What I care about #

Privacy, decentralisation, and tools that are honest about what they protect and what they don’t. In my spare time I build small things like tw-split, which keeps my private notes encrypted on GitHub Pages.

What I do #

• Cloud and Kubernetes security assessments
• Penetration tests, black box and white box
• Scenario-based red teaming
• Trainings and coaching