https://stefansiegl.de/Recent content on ~stesie's musingsHugo -- 0.123.7en-us2025 Stefan Siegl · all content is CC-BY-SA · Terms of ServiceThu, 19 Mar 2026 00:00:00 +0000https://stefansiegl.de/2026/03/keycloak-token-exchange/Thu, 19 Mar 2026 00:00:00 +0000https://stefansiegl.de/2026/03/keycloak-token-exchange/At Bar-Code Developer Barcamp last week someone mentioned a feature named On behalf of in Microsoft Entra (in the context of a user requesting an Agent/LLM to query the database on her behalf). That lead me to the question: does keycloak support this as well? And indeed it does. In Keycloak it’s just called Token Exchange and was introduced as a stable feature in Keycloak 26.2 So given a ui client, and orchestrating backend client (named cxc) and multiple resource servers (e.https://stefansiegl.de/2026/02/first-steps-with-jujutsu/Fri, 06 Feb 2026 00:00:00 +0000https://stefansiegl.de/2026/02/first-steps-with-jujutsu/So the other day I started using Jujutsu … for the moment “just” with two repositories at work. But willing to learn and potentially ramp up usage. This is after Daniel Danner was “advertising” it on last year’s Seneca Camp in Erlangen. Motivation Reason for trying it out is that I want to benefit from Jujutsu megamerges and the jj absorb feature. So at work I’m currently working on a single long-running project, and most of the time working alone on some feature branches in parallel.https://stefansiegl.de/2026/02/sandboxing-with-systemd-run/Mon, 02 Feb 2026 00:00:00 +0000https://stefansiegl.de/2026/02/sandboxing-with-systemd-run/So this applies to all coding agents, but I’m just exercising it with aider here. TBH I even trust aider pretty much and have more concerns with other beasts like Codename Goose, Claude Code, PI and others … … so in order to constrain those tools I first went with Docker … which felt like a natural choice. Especially since I’m pretty fluent with it … which I unfortunately still cannot say is true regarding systemd.https://stefansiegl.de/2025/06/dependency-inversion-for-camunda-tasks/Thu, 19 Jun 2025 00:00:00 +0000https://stefansiegl.de/2025/06/dependency-inversion-for-camunda-tasks/In Camunda Service Tasks can be implemented using so-called delegate expressions, which, in the context of CDI, resolve to @Named annotated beans. This task class has to implement the JavaDelegate interface, which mandates a method named execute, which receives a single argument with a DelegateExecution instance. However there is the Dependency Inversion Principle (DIP), and this way our business code directly depends on two classes from Camunda. Can’t we do better?https://stefansiegl.de/2025/03/building-wueride-experimenting-with-llm-powered-coding-and-the-fediverse/Sun, 30 Mar 2025 00:00:00 +0000https://stefansiegl.de/2025/03/building-wueride-experimenting-with-llm-powered-coding-and-the-fediverse/A few weeks ago, I came across Harper Reed’s blog post, My LLM codegen workflow atm, which made the rounds in the developer community. While his approach to using a LLM to collect and refine requirements was interesting, … what really caught my attention was him mentioning, that he uses Aider to let LLMs modify his code. So what is Aider? Simply put, Aider is a CLI tool that isn’t tied to a specific LLM.https://stefansiegl.de/2025/03/wayland-support-in-intellij/Tue, 18 Mar 2025 00:00:00 +0000https://stefansiegl.de/2025/03/wayland-support-in-intellij/Today I learned, that IntelliJ has support for Wayland Compositor since version 2024.2, so seems like im rather late to the game. Simply go to Help > Edit custom VM options and add -Dawt.toolkit.name=WLToolkit. For me it so far works nicely. And the issue of some overlay windows (like object inspector) not being resizable in Sway … are just gone. Yay 🥳https://stefansiegl.de/2025/03/scripting-intellij/Mon, 17 Mar 2025 00:00:00 +0000https://stefansiegl.de/2025/03/scripting-intellij/Recently I learned, that it’s possible to script IntelliJ. I picked up on it while Writing an IntelliJ Plugin for my Coverage Tracker project, aka “Undercovered”. So there is the IDE scripting console, which comes out-of-the-box. You just open the Action panel and search for IDE Scripting Console, next a tiny popup menu should show, asking for whether it should be Groovy or Kotlin (beta). Right away you can enter some code and evaluate it by pressing Control + Return.https://stefansiegl.de/2025/03/writing-an-intellij-plugin/Tue, 04 Mar 2025 00:00:00 +0000https://stefansiegl.de/2025/03/writing-an-intellij-plugin/In a way, this is the last part of my journey creating a Java (Line) Coverage Analyzer. This article concentrates on creating an IntelliJ plugin, that adapts it to show the results collected by the analyzer created in Let’s create a Coverage Analyzer, Part 4. To get started, check out JetBrains’ Developing a Plugin article. With recent IntelliJ versions you need to install the Plugin DevKit first, then create a new Project and select the IDE Plugin Generator.https://stefansiegl.de/2025/03/lets-create-a-coverage-analyzer-part-4/Sat, 01 Mar 2025 18:30:00 +0000https://stefansiegl.de/2025/03/lets-create-a-coverage-analyzer-part-4/This is part four of my journey creating a Java (Line) Coverage Analyzer. This time around we’ll test the implementation created in part three and look into details what still goes wrong. One (simplified) example that crashes the current analyzer implementation is this one: public class Demo3 { public static void main(final String[] argv) { final Stuff stuff = new Stuff( !getBoolean()); bla("value: " + stuff.boolValue()); } public static boolean getBoolean() { return true; } private static void bla(final String greeting) { System.https://stefansiegl.de/2025/03/lets-create-a-coverage-analyzer-part-3/Sat, 01 Mar 2025 11:00:00 +0000https://stefansiegl.de/2025/03/lets-create-a-coverage-analyzer-part-3/This is part three of my journey creating a Java (Line) Coverage Analyzer. This time around we’ll look into improving the very naive implementation created in part two. That one ended in a VerifyError and the message Expecting a stackmap frame at branch target 41 So what is this branch target, and the stackmap frame that it’s suddenly missing? To have an easier time inspecting the Byte Code, let’s first create a little CLI version of our instrumentation code.https://stefansiegl.de/2025/02/lets-create-a-coverage-analyzer-part-2/Wed, 26 Feb 2025 00:00:00 +0000https://stefansiegl.de/2025/02/lets-create-a-coverage-analyzer-part-2/This is part two of my journey creating a Java (Line) Coverage Analyzer. Here we’ll actually implement the Byte Code Instrumentation, as pointed out in the first part. Since processing the Byte Code itself, i.e. reading the classes, finding the methods, processing line number information, is in itself a huge task, let’s rely on the ASM library for that. After all JaCoCo and Cobertura also rely on that, so this seems to be a valid choice 😂https://stefansiegl.de/2025/02/lets-create-a-coverage-analyzer-part-1/Mon, 17 Feb 2025 00:00:00 +0000https://stefansiegl.de/2025/02/lets-create-a-coverage-analyzer-part-1/Have you ever wondered what happens when you click on “Run with Coverage” in IntelliJ? Obviously it’s running the tests, but how is it collecting the coverage information? Let’s create a simple Line Coverage Analyzer in and for Java 🥳 First of all, let’s write a simple example program (see GitHub) package de.brokenpipe.dojo.undercovered.demo; public class Demo { public static void main(final String[] argv) { final String greeting = "Hello World"; bla(greeting); bla("to the blarg"); } private static void bla(final String greeting) { System.https://stefansiegl.de/2025/02/chromium-site-search/Mon, 03 Feb 2025 00:00:00 +0000https://stefansiegl.de/2025/02/chromium-site-search/Pretty likely this is a well-known thing to many 🥱, and to be honest, I also kindof knew that Chromium has some search shortcuts, but I never bothered to learn how to use them. To even add to that, I’m even well aware that I quite regularly went to pages like dict.leo.org, and used the search feature there. Or I went to our Jira instance, and used the search feature there, regularly just typing a ticket number.https://stefansiegl.de/2025/02/other-llms-writing-a-telegram-bot/Sun, 02 Feb 2025 00:00:00 +0000https://stefansiegl.de/2025/02/other-llms-writing-a-telegram-bot/This is the fourth (and likely last) part in this mini series. ℹ️ This post belongs to a mini series (I’m aiming for three posts in a row), where I try prompting Claude with different levels of verbosity and compare the results: In Claude writing a Telegram Bot, 1st try I’m using an elaborate, step-by-step prompting strategy with Haiku model In Claude writing a Telegram Bot, 2nd try I aim for a detailed one-shot prompt In Claude writing a Telegram Bot, 3rd try I try a rather short one-shot prompt In Other LLMs writing a Telegram Bot I quickly try DeepSeek and some more LLMs Since DeepSeek currently is all the rage, obviously I had to prompt it as well.https://stefansiegl.de/2025/02/claude-writing-a-telegram-bot-3rd-try/Sat, 01 Feb 2025 00:00:00 +0000https://stefansiegl.de/2025/02/claude-writing-a-telegram-bot-3rd-try/This is the third part of the mini series on writing Telegram bots to read my gas meter using Claude. ℹ️ This post belongs to a mini series (I’m aiming for three posts in a row), where I try prompting Claude with different levels of verbosity and compare the results: In Claude writing a Telegram Bot, 1st try I’m using an elaborate, step-by-step prompting strategy with Haiku model In Claude writing a Telegram Bot, 2nd try I aim for a detailed one-shot prompt In Claude writing a Telegram Bot, 3rd try I try a rather short one-shot prompt In Other LLMs writing a Telegram Bot I quickly try DeepSeek and some more LLMs Like in the first round, I will once more show the full dialog I’ve used to let it generate the implementation.https://stefansiegl.de/2025/01/audio-journaling/Thu, 30 Jan 2025 00:00:00 +0000https://stefansiegl.de/2025/01/audio-journaling/For quite some time now, I’ve been using Logseq as my personal knowledge management system. It has been an invaluable tool for organizing my thoughts, projects, and ideas. A few months ago, I decided to take it a step further by incorporating journaling into my daily routine. Each morning and evening, I reflect on how I’m feeling, what has moved me, what went well during the day, where I excelled, and where there might be room for improvement.https://stefansiegl.de/2025/01/claude-writing-a-telegram-bot-2nd-try/Tue, 28 Jan 2025 00:00:00 +0000https://stefansiegl.de/2025/01/claude-writing-a-telegram-bot-2nd-try/This is the second part of the mini series on writing Telegram bots to read my gas meter using Claude. ℹ️ This post belongs to a mini series (I’m aiming for three posts in a row), where I try prompting Claude with different levels of verbosity and compare the results: In Claude writing a Telegram Bot, 1st try I’m using an elaborate, step-by-step prompting strategy with Haiku model In Claude writing a Telegram Bot, 2nd try I aim for a detailed one-shot prompt In Claude writing a Telegram Bot, 3rd try I try a rather short one-shot prompt In Other LLMs writing a Telegram Bot I quickly try DeepSeek and some more LLMs Like in the first round, I will first show the full dialog I’ve used to let it generate the implementation.https://stefansiegl.de/2025/01/claude-writing-a-telegram-bot-1st-try/Mon, 27 Jan 2025 00:00:00 +0000https://stefansiegl.de/2025/01/claude-writing-a-telegram-bot-1st-try/Below you’ll find results of my initial try in using Claude to write a Telegram Bot. ℹ️ This post belongs to a mini series (I’m aiming for three posts in a row), where I try prompting Claude with different levels of verbosity and compare the results: In Claude writing a Telegram Bot, 1st try I’m using an elaborate, step-by-step prompting strategy with Haiku model In Claude writing a Telegram Bot, 2nd try I aim for a detailed one-shot prompt In Claude writing a Telegram Bot, 3rd try I try a rather short one-shot prompt In Other LLMs writing a Telegram Bot I quickly try DeepSeek and some more LLMs My ultimate goal is to figure out how much gas I need to heat my apartment.https://stefansiegl.de/2025/01/shift-left-testing-mit-automatischer-anforderungsabdeckung/Sun, 12 Jan 2025 00:00:00 +0000https://stefansiegl.de/2025/01/shift-left-testing-mit-automatischer-anforderungsabdeckung/Am 29. Juni war ich auf dem wunderbaren 6. SoCraTes Day Franken (große Empfehlung, falls es eine nächste Version geben wird). In der Session „Shift Left Testing“ von Felix Tensing beleuchtete er die Herausforderungen und seine Lösungsansätze im Bereich der Software-Anforderungsabdeckung. Hierbei stellte er sein Konzept vor, das speziell das Problem von inhaltlich veralteten oder unvollständigen Jira-Tickets adressiert. Problemstellung Jira-Tickets oder ähnliche Systeme dienen dazu, Anforderungen und Aufgaben im Entwicklungsprozess festzuhalten.https://stefansiegl.de/2025/01/learning-out-loud/Mon, 06 Jan 2025 00:00:00 +0000https://stefansiegl.de/2025/01/learning-out-loud/Lately, I’ve come across the concepts of “learning in public” and “digital gardens.” A digital garden is a unique approach to organizing and sharing knowledge in a non-linear and evolving manner. Think of it as a personal wiki where one can cultivate ideas, insights, and resources over time. Unlike traditional blogs or websites that present polished and finalized content, digital gardens focus on capturing the learning process itself, fostering exploration and serendipitous connections between different pieces of information.https://stefansiegl.de/2025/01/switching-to-sway/Thu, 02 Jan 2025 00:00:00 +0000https://stefansiegl.de/2025/01/switching-to-sway/I recently switched from i3 to the Sway window manager on Ubuntu Linux 24.04, exploring its flexibility and learning to configure it for my needs. I customized keybindings, set up tools like swayidle and swaylock-effects for screen locking, and used kanshi for monitor management and mako for notifications. While it required more manual effort than GNOME or macOS, the result is a highly personalized and functional setup.https://stefansiegl.de/2024/12/rediscovering-programmer-dvorak/Sat, 28 Dec 2024 00:00:00 +0000https://stefansiegl.de/2024/12/rediscovering-programmer-dvorak/About 15 years ago, I stumbled upon the Programmer Dvorak keyboard layout, which completely changed how I thought about typing. This Christmas, I decided to see if my fingers still remembered the layout, and to my surprise, they did—better than my mind could! The experience reignited my love for customizing tools, and I even set up my current system to bring back the layout, blending nostalgia with practicality.https://stefansiegl.de/2024/12/junit-parameter-resolvers/Wed, 11 Dec 2024 00:00:00 +0000https://stefansiegl.de/2024/12/junit-parameter-resolvers/Today (err, recently) I learned … that JUnit’s extension API allows for parameter resolvers. These kick in every time you use arguments on a test method, lifecycle method or class constructor. For me, so far, none of these methods ever took an argument. But turns out, it’s possible … and even useful. They have a primitive example here where they allow a test method to take a random number like so: