Luis Henrich-Bandis

23 · Cologne · Master’s at RWTH Aachen

Hi, I’m Luis. I’m 23, I build things, and the last two years of my life have basically been one thing: StudyPDF.

We started it in summer 2024. A friend, his exam prep, and ChatGPT failing at PDFs in spectacularly stupid ways. I built the first version in three weeks. Two years later it’s at 100,000+ users across 200+ universities, around 600 daily actives, 150k+ documents processed, and I run it solo from Cologne. I do all of it: the AI pipeline, the infra, the support emails, the SEO posts, the late-night bug that turned out to be a vector store leaking across users while I was on holiday in Madeira. Obviously not everything works the first time. You learn by breaking things in production.

Most of the interesting work has been on the AI side. The product runs on a two-stage extraction pipeline: an expensive reasoning model reads the document once, extracts topics and concepts, and every other feature (flashcards, practice questions, mind maps, the chat layer) is generated against that same tree. Cost goes down, quality goes up. I wrote the long version here.

I write here when something is actually worth writing about. Usually something I learned the hard way. Running a company while still in school, using Claude Code as a small team, multi-agent pipelines that hold up at exam-season load. No content calendar, no thread bait. Six honest posts a year is fine.