Making Of: Aareschwumm Datenplakat 2025

It has now become something of a tradition for me to create a data poster at the end of the summer Aareschwumm season, which is available in the Aare Guru Shop or in the poster cellar.

This year's data is rather uninteresting. There were three days of flooding, but otherwise nothing remarkable happened in terms of hydrology or meteorology. So I decided to make the poster as colorful as possible and create it using scripting instead of making the data as legible as possible and formatting it in the usual way.

The different values are represented by simple symbols, with the size and color representing the value of the file entry. To write the scripts that control Adobe Illustrator, I used openrouter.ai and vibe coded the whole thing. Since LLMs can be extremely tedious and only produce garbage, you can easily switch models on this website if the output is unusable.

Github repo with the finished scripts: Github repo Aare Guru Symbol Generator

Adobe scripting is quite difficult, and I would never have managed it without LLMs. When it comes to scripting via LLMs, it must be said that you still need to be able to read and understand the code. I advise against simply generating something blindly. And in the end, a human on Stack Exchange helped me fix the last bug—old school still works.

The reason why it's better to write a script via LLM and not do the generation directly via LLM is because the error rate is so absurdly high that it makes no sense to have an LLM do it.

After generating all symbols, everything is distributed manually on the A2 poster. Formal aesthetic considerations play a role here. Or in other words: it should look exciting.

And this is how the finished data poster ultimately turned out. It was my first experience with scripting. Let's see how things progress next year. The poster is available online in our Aare Guru Shop, or you can see it in real life at Plakatkeller on Münsterplatz in Bern.