A Java geek

From documenting decisions to questioning them

I started with a simple task: I needed an AI agent to help me compile decision records, structured documents that capture why a team chose option A over B, using the open-source MADR format. Fill in the sections, organize the rationale, done. It worked. And it was useless.

Technical

AI-assisted genealogy, a follow-up

I got a lot of feedback on my post AI-assisted genealogy, some good, some not so good. In any case, I felt the subject was interesting to a lot of people. Meanwhile, I continue working on my tree, and I have deepened my understanding of the subject. In this post, I want to share again. Trust, but verify Let’s address the not-so-good feedback first. The gist of it was: AI can hallucinate. It’s true in theory: when you ask a question, it provides any answer.

Miscellaneous

World geography gotchas

Years ago, a colleague of mine told me about two pockets of foreign land surrounded by Switzerland: Campione d’Italia and Büsingen am Hochrhein, respectively Italy and Germany. Both are enclaves of their respective country in Swiss territory: An enclave is a part of the territory of a state that is enclosed within the territory of another state. To distinguish the parts of a state entirely enclosed in a single other state, they are called true enclaves.

Book

Build an AI Agent (From Scratch)

Facts 10 chapters$29.29 (at the time of this writing)315 pages Chapters Building your first LLM agentWhat is an AI agent?

Technical

AI-assisted genealogy

My son recently came to me to brag about using AI to find our ancestors. While the results were correct, I didn’t learn anything new, as it stopped at my grandparents. I was never very interested in my genealogy, but I decided to see if AI would be a good tool for this. TL;DR: Yes, it is, and even more than that. In a little less than one month, I managed to gather more than 600 individuals and get back 12 generations in some branches.

Technical

Security Baked Into the JVM: sixteen Subjects on the wire

Alice calls the order service. The order service calls the ledger on her behalf. At the second hop, the ledger has to decide whose authority the debit is being made under. Most stacks answer badly. Forward Alice’s bearer token verbatim, and the ledger cannot tell her from the service that relayed it. Drop the token and the ledger sees a machine, with no record that a human started the chain. Neither option lets the ledger authorize the combination.

Development

Solving Gradle metadata and Renovate integration

My current company has settled on using Gradle. It doesn’t make me very happy, but you need to learn to work with constraints. Plus, I must admit that the developers who actually implemented the build files did a pretty good job overall: they used Kotlin instead of Groovy, they moved code to regular plugins, etc. This week, I worked on improvements to a new project and set up Renovate.

Technical

Security Baked Into the JVM: two Subjects, one call

The constraint system stops a bad call before it leaves the JVM. The Safe Codebase Audit Pipeline stops bad code before a client ever loads it. What remains is identity: who is calling, and can you verify it? Most frameworks answer with a token check at the door. A filter validates a bearer token, sets a thread-local variable, and hopes that nothing downstream forgets to look at it. DirtyChai answers differently.

Technical

GitHub agentic workflows and Renovate

I’ve been a big fan of Renovate for a couple of years already. Renovate scans your repositories, detects outdated package versions, and opens pull requests to automatically bump them. It’s similar to Dependabot in that it keeps your dependencies up to date. If I had to compare them in one sentence, I’d say Renovate is less integrated in the GitHub ecosystem, but handles more ecosystems and, more importantly, is extensible.

A Java geek

Nicolas Fränkel's blog