Things I've built outside of client work: tools, open source, and two books. Side projects are where I get to new technology first — at the moment that means AI engineering and agentic development.
A terminal AI coding agent built from scratch on the raw Anthropic SDK. Includes an agentic loop, bash and text editor tools, sandboxing, plan mode, skills, and an eval suite.
I started this project to understand the details of an agentic loop. It turned out that with a few tools and a minimal TUI, the loop becomes a real coding agent.
Built with TypeScript and Bun.
A macOS app that renames document filenames according to document contents. The app uses an LLM to read the document contents and generate a new filename.
The idea came from a problem I had: For my company, I needed to rename a lot of invoices for correct accounting. I had to rename them by hand, one by one. I felt there must be a better way.
Built with Tauri, React, TypeScript, Rust, and the Vercel AI SDK.
Every book designer who has built a page plan in InDesign knows the moment: you need to insert a page, and every following page tile has to be moved by hand, every page number updated, one by one. On a 600-page book, that is a lot of work.
“Every time I had to insert a page, I felt like crying.”
Simona, book designer
Many designers skip the page plan entirely and just hold the structure in their head, even though clients want one. I have built Recto to make it easier for designers.
Recto is a visual flat-plan tool for print designers that visualizes a publication the way books are actually made: As pages, spreads, and print sheets.
Built with React, TypeScript, React Router 7, and Supabase.
Two books:
Spring und Hibernate – Eine praxisbezogene Einführung introduces Spring and Hibernate and how the two work together in a typical project. Co-authored with Oates, Langer, Lueckow, Bachlmayr. Hanser, 2006; second edition 2008. Amazon's page.
Go To Java Server Pages introduces Java Server Pages for Java developers, from the basics to building web applications. Addison-Wesley, 2001. Amazon's page.
