'97 Things Every SRE Should Know' book notes
These are my personal book notes of Emil Stolarsky's and Jaime Woo's '97 Things Every SRE Should Know'. They are for myself, but I hope they might be useful to you too.
foo.zone feed
To be in the .zone!
Latest posts
'Eat That Frog' book notes
These are my personal book notes from Brian Tracy's 'Eat That Frog!' They are for myself, but I hope they might be useful to you too.
Unveiling Hexai: An AI companion for Helix and the terminal in general
I have been using Helix as my main editor for a while now. It is fast, modal, and stays out of the way. The one thing I missed was a bit of LLM help without leaving the editor or opening a browser tab. So I built Hexai.
Posts from January to June 2026
Hello there! These are my social media posts from the last six months. I keep them here to reflect on them and also to not lose them. Social media networks come and go and are not under my control, but my domain is here to stay.
Random Weird Things - Part Ⅳ
Every so often I stumble upon random, weird, and completely unexpected things on the internet. I thought it would be neat to share them here from time to time. This is the fourth run.
`gt` calculator - a calculator built with local LLMs
I created a calculator. Not because the world needed another one, but because I wanted to test something: How well do local LLMs hold up as pair programmers on a real project? I want to be independent of the big LLM providers like Anthropic, OpenAI, and company for this `gt`-project.
Unveiling I/O Riot NG — Part 3: under the hood
This is the third and final post in the series. Part 1 is the demo-driven tour: what ior looks like, how the dashboard tabs work, how the live flamegraph reads, how filtering and recording behave. Part 2 covers the install dance for Rocky Linux 9 and the 'compile once, run everywhere' portability story (eBPF, CO-RE, libbpfgo, static linking). This one is the part you read when you've got ior…
Unveiling I/O Riot NG — Part 2: install and compile once, run everywhere
This is Part 2 of three. Part 1 is the demo-driven tour: what ior looks like, how the dashboard tabs work, how filtering and recording behave. This part is about the installation for Rocky Linux 8 and 9 and, more interestingly, why you only have to do that dance on a single machine: the resulting binary is portable to every other Linux box thanks to CO-RE (Compile Once, Run Everywhere) plus full…
Unveiling I/O Riot NG — Part 1: a guided tour
I rewrote I/O Riot. The old version, written in C and SystemTap, dates back to 2017. The new version (called `ior`) uses Go, C, and BPF via libbpfgo. It runs on Linux and is primarily a TUI dashboard rather than a record/replay box. It took around two years of intermittent work to reach this `1.0.0` release.
f3s: Kubernetes with FreeBSD - Part 9: GitOps with ArgoCD
This is the 9th post in the f3s series about my self-hosting home lab. f3s? The 'f' stands for FreeBSD, and the '3s' stands for k3s, the Kubernetes distribution I use on FreeBSD-based physical machines.
Distributed Systems Simulator - Part 3: Advanced Examples and Protocol API
This is the third and final blog post of the Distributed Systems Simulator series. This part covers advanced simulation examples, the Raft consensus protocol, and the extensible Protocol API.
Distributed Systems Simulator - Part 2: Built-in Protocols
This is the second blog post of the Distributed Systems Simulator series. This part covers all 10 built-in protocols with examples.
Distributed Systems Simulator - Part 1: Introduction and GUI
This is the first blog post of the Distributed Systems Simulator series, written for the recent v1.1.0 release. It explores the Java-based Distributed Systems Simulator program I created as my diploma thesis at the Aachen University of Applied Sciences (August 2008). The simulator offers both built-in implementations of common distributed systems algorithms and an extensible framework that allows…
RCM: The Ruby Configuration Management DSL
RCM is a tiny configuration management system written in Ruby. It gives me a small DSL for describing how I want my machines to look, then it applies the changes: create files and directories, manage packages, and make sure certain lines exist in configuration files. It's deliberately KISS and optimised for a single person's machines instead of a whole fleet.
Site Reliability Engineering - Part 5: System Design, Incidents, and Learning
Welcome to Part 5 of my Site Reliability Engineering (SRE) series. I'm currently working as a Site Reliability Engineer, and I'm here to share what SRE is all about in this blog series.
Loadbars 0.13.0 released
Loadbars is a real-time server load monitoring tool. It connects to one or more Linux hosts via SSH and shows CPU, memory, network, load average, and disk I/O as vertical colored bars in an SDL window. You can run it locally or point it at your servers and see what's happening right now — like `top` or `vmstat`, but visual and across multiple hosts at once.
My desk rack: DeskPi RackMate T0
On my desk sits a small rack that keeps audio gear, power, and network in one place: the DeskPi RackMate T0. Here's what lives in it and how it's wired.
A tmux popup editor for Cursor Agent CLI prompts
I spend some time in Cursor Agent (the CLI version of the Cursor IDE, I don't like really the IDE), and I also jump between Claude Code CLI, Ampcode, Gemini CLI, OpenAI Codex CLI, OpenCode, and Aider just to see how things are evolving. But for the next month I'll be with Cursor Agent.
Using Supernote Nomad offline
I am a note taker. For years, I've been searching for a good digital device that could complement my paper notebooks. I've finally found it in the Supernote Nomad. I use it completely offline without cloud-sync, and in this post, I'll explain why this is a benefit.
Cloudless Kobo Forma with KOReader
I am an reader, and for years I've been searching for a good digital e-reader to complement my paper books. I advocate for privacy-first and prefer open-source or self-hosted solutions. If that is not possible, I opt for offline solutions. Even if I don't have anything to hide, the tinkerer in me wants those things anyway. I found my ideal device in the Kobo Forma 7 years ago. Now, I use it…
Posts from July to December 2025
Hello there, I wish you all a happy new year! These are my social media posts from the last six months. I keep them here to reflect on them and also to not lose them. Social media networks come and go and are not under my control, but my domain is here to stay.
X-RAG Observability Hackathon
This post describes my hackathon efforts adding observability to X-RAG, the extensible Retrieval-Augmented Generation (RAG) platform built by my brother Florian. I made time over the weekend to join his 3-day hackathon (attending 2 days) with the goal of instrumenting his existing distributed system with observability. What started as 'let's add some metrics' turned into a comprehensive…
f3s: Kubernetes with FreeBSD - Part 8b: Distributed Tracing with Tempo
This is a follow-up to Part 8 of the f3s series, where I covered Prometheus, Grafana, Loki, and Alloy. Now it's time for the last pillar of observability: distributed tracing with Grafana Tempo.
'The Courage To Be Disliked' book notes
These are my personal book notes from Ichiro Kishimi and Fumitake Koga's 'The Courage To Be Disliked'. They are for me, but I hope they might be useful to you too.
Perl New Features and Foostats
Perl recently reached rank 10 in the TIOBE index. That headline made me write this blog post as I was developing the Foostats script for simple analytics of my personal websites and Gemini capsules (e.g. `foo.zone`) and there were a couple of new features added to the Perl language over the last releases. The book *Perl New Features* by brian d foy documents the changes well; this post shows how…
Key Takeaways from The Well-Grounded Rubyist
Some time ago, I wrote about my journey into Ruby and how 'The Well-Grounded Rubyist' helped me to get a better understanding of the language. I took a lot of notes while reading the book, and I think it's time to share some of them. This is not a comprehensive review, but rather a collection of interesting tidbits and concepts that stuck with me.
Bash Golf Part 4
This is the fourth blog post about my Bash Golf series. This series is random Bash tips, tricks, and weirdnesses I have encountered over time.
Random Weird Things - Part Ⅲ
Every so often, I come across random, weird, and unexpected things on the internet. It would be neat to share them here from time to time. This is the third run.
Local LLM for Coding with Ollama on macOS
With all the AI buzz around coding assistants, and being a bit concerned about being dependent on third-party cloud providers here, I decided to explore the capabilities of local large language models (LLMs) using Ollama.
Posts from January to June 2025
These are my social media posts from the last six months. I keep them here to reflect on them and also to not lose them. Social media networks come and go and are not under my control, but my domain is here to stay.
Task Samurai: An agentic coding learning experiment
Task Samurai is a fast terminal interface for Taskwarrior written in Go using the Bubble Tea framework. It displays your tasks in a table and allows you to manage them without leaving your keyboard.
'A Monk's Guide to Happiness' book notes
These are my personal book notes from Gelong Thubten's 'A Monk's Guide to Happiness: Meditation in the 21st century.' They are for my own reference, but I hope they might be useful to you as well.
Terminal multiplexing with `tmux` - Fish edition
This is the Fish shell edition of the same post (but for Z-Shell) of mine from last year:
'When: The Scientific Secrets of Perfect Timing' book notes
These are my personal book notes from Daniel Pink's 'When: The Scientific Secrets of Perfect Timing.' They are for me, but I hope they might be useful to you too.
Sharing on Social Media with Gos v1.0.0
As you may have noticed, I like to share on Mastodon and LinkedIn all the technical things I find interesting, and this blog post is technically all about that.
Random Weird Things - Part Ⅱ
Every so often, I come across random, weird, and unexpected things on the internet. I thought it would be neat to share them here from time to time. This is the second run.
f3s: Kubernetes with FreeBSD - Part 3: Protecting from power cuts
This is the third blog post about my f3s series for my self-hosting demands in my home lab. f3s? The 'f' stands for FreeBSD, and the '3s' stands for k3s, the Kubernetes distribution we will use on FreeBSD-based physical machines.
f3s: Kubernetes with FreeBSD - Part 8: Observability
This is the 8th blog post about the f3s series for my self-hosting demands in a home lab. f3s? The 'f' stands for FreeBSD, and the '3s' stands for k3s, the Kubernetes distribution I use on FreeBSD-based physical machines.
f3s: Kubernetes with FreeBSD - Part 7: k3s and first pod deployments
This is the seventh blog post about the f3s series for my self-hosting demands in a home lab. f3s? The 'f' stands for FreeBSD, and the '3s' stands for k3s, the Kubernetes distribution I use on FreeBSD-based physical machines.
f3s: Kubernetes with FreeBSD - Part 6: Storage
This is the sixth blog post about the f3s series for self-hosting demands in a home lab. f3s? The 'f' stands for FreeBSD, and the '3s' stands for k3s, the Kubernetes distribution used on FreeBSD-based physical machines.
f3s: Kubernetes with FreeBSD - Part 5: WireGuard mesh network
This is the fifth blog post about my f3s series for my self-hosting demands in my home lab. f3s? The 'f' stands for FreeBSD, and the '3s' stands for k3s, the Kubernetes distribution I will use on FreeBSD-based physical machines.
f3s: Kubernetes with FreeBSD - Part 4: Rocky Linux Bhyve VMs
This is the fourth blog post about the f3s series for self-hosting demands in a home lab. f3s? The 'f' stands for FreeBSD, and the '3s' stands for k3s, the Kubernetes distribution used on FreeBSD-based physical machines.