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🤔 What’s a syscall, anyway? Image credits: Mike Norris via Pexels Every time your program reads a file, writes to a socket, or allocates memory, at some point it has to ask the kernel to actually do it. That ask is a syscall, the narrow, well defined boundary where userspace code crosses into the kernel. write(), read(), open(), mmap(), these aren’t just library functions, they’re the entire vocabulary your program has for talking to the outside world. Everything else, fwrite, Python’s file.write(), std::fs::File, is just a wrapper around this same handful of kernel entry points. ...

📝 Too Long; Didn’t Read We are already at the halfway mark of 2026, and these first six months have been intense. Between coding, conferences, and workshops across Europe, I worked on systems management, green computing, local AI, and software security. This post is a recap of the projects and talks that shaped my February-to-June journey. 🛠️ February to May: deep dive into the Uyuni project For the first four months of this year, my main engineering focus was almost entirely dedicated to the fascinating world of the Uyuni project. If you have not had a chance to work with it yet, Uyuni is an incredibly powerful, completely open-source configuration and infrastructure management solution. It originally started as an evolution of Spacewalk, and today it serves as the upstream community project that feeds directly into SUSE Multi-Linux Manager, which was formerly known as SUSE Manager. ...

🧭 Where we left off Welcome back to our ongoing series on measuring test coverage for binary programs! In part 1 we used Go’s built-in -cover flag — clean and accurate, but only works if you own the source and can recompile. In part 2 we used valgrind and gdb to trace gzip without touching its source. In part 3 we explored Intel PIN, a proper dynamic binary instrumentation framework — powerful, but it came with a ~100MB proprietary C++ SDK and was limited to x86_64. ...

📦 That new package smell We’ve all been there: you see a shiny new app on GitHub and you want to “unwrap” it immediately. But in the traditional Linux world, opening a package often feels like opening a box of glitter in your living room—before you know it, dependencies are scattered everywhere, and you’re still finding weird library versions in /usr/lib three months later. This is why I’ve started reaching for the Flatpak. It’s like an unboxing experience where the box stays a box. You get all the “goodies” inside, but the mess stays contained. Let’s see what happens when we tear off the shrink-wrap. ...