After two and a half years away from blogging, I am starting again with a new approach. What began as a way to showcase my skills has shifted. Now I am writing to keep a personal record of the projects and experiences that have shaped my journey..

Last month, I relocated from Karlsruhe, Germany to Amsterdam, the Netherlands. My two primary motivations have been the desire to live in a different country and a job offer that sparked my interest. It has been quite an adventure so far and I wanted to share my experiences.

Sometimes I need to create certificates for testing purposes. For example, I set up an etcd cluster by hand recently. This happens rarely enough that I need to look up the openssl syntax every time.

Sometimes, issues can only be fixed in a layer below the abstractions you rely on usually. Understanding the whole stack as much as possible is a great advantage when a bug pops up. For this reason, I decided to implement a simple Linux syscall to become familiar with the Linux kernel’s code organization. That said, I don’t aspire to become a kernel hacker. The new syscall printk simply prints a given null-terminated message into the kernel log.

When I started this blog at the end of 2018, I didn’t want to spend much time on the blog’s setup, but rather get started writing as soon as possible. For this reason, I chose a preconfigured VM image with the blogging software Ghost that was offered by my cloud provider. In the meantime, writing has become a hobby to me, even though I keep most of what I write private.

Another year, another Hacktoberfest. This year, I created a basic ray tracer and also contributed to a Prometheus exporter.

I received an interesting E-Mail from my ISP recently. It said (translated from german): "Security warning: we detected an open DNS resolver on your system. Open DNS resolvers can be misused for DDoS reflection attacks against third parties. I was indeed running a publicly exposed DNS server that acted as nameserver for a domain. After I secured my DNS server, I decided to explore the mentioned DDoS reflection attacks.