In the DI² application a validation rule could not be saved. The dialog offered the user a column that had not yet been selected in the project. A click on that column should have selected it. In one particular case it did not, and the server rejected the rule. A coding agent wrote a fix. … Read more
In mid-September 2026 the catalog of manual test cases in the DI² project had 32 active entries. 27 of them existed only because something had been broken before. For just two test cases, what has to be visible on screen was settled before the code existed. A catalog that came almost entirely from bugs secures … Read more
A manual test case in the DI² project had everything the convention asks for: a header with goal and precondition, a step table with step and expectation, an entry in the catalog overview, references to the files it covers. The catalog’s automatic structural check had accepted it. On the first execution it turned out that … Read more
A bug on the DI² project’s website counted as fixed for four weeks. When the reader switches the language, the page is supposed to stay at the spot where the reader was. Three fix commits had promised that one after another, each with its own diagnosis, and after each one the automated test suite was … Read more
Reading code in order to control it takes two things: the language and the time. In the DI² project, both are missing. The maintainer comes from database development and knows neither TypeScript nor the web development the application is built in. And even someone who knows the language no longer reads through the amount of … Read more
A bug gets reported the way it feels: the message does not appear, the page barely responds, a tab no longer loads after a restart. A user can only describe what the interface shows, and the interface is the end of a long chain. A coding agent with access to the database, the container runtime … Read more
“We host in Frankfurt, so we’re GDPR-compliant.” The sentence comes up in almost every conversation about Vercel and Supabase, and it is half the answer to a question that has two halves. The region answers where the data lives. It does not answer whose law applies to the companies that process that data. This article … Read more
For most web applications, the cookie banner question comes up too late. The application is built, an analytics script is in, the login page comes from a cloud service, and suddenly the very first page view needs a consent dialog that nobody planned for. The DI² project turned the question around. GDPR without a cookie banner was … Read more
A Claude Code session opens a Git repository with no pending changes, works for half an hour and commits whatever has changed at the end. Run alone, that is correct. As soon as a second session or a human works in the same repository, the very same routine can pull someone else’s work into the … Read more
Since spring 2026, two projects have been taking shape with the same coding agent: an ETL generator on Next.js and PostgreSQL, and this blog. The agent does not complete lines, it works through assignments in the repository. This article collects my agentic coding experience from a user’s perspective. I build databases, ETL processes and the … Read more
