Side builds
Small tools and apps born from a "what if I just made this myself?" moment.
Personal site
A workshop for personal projects and AI experimentation.
Welcome. I'm Tjerk Spijkman. This is my corner of the web — a place where I build things for the fun of it, tinker with ideas, and run experiments with AI and machine learning. Nothing here is a product; it's a lab notebook made public.
Projects
Things I'm making, breaking, and rebuilding.
HeroRPG
A browser role-playing game, built by Claude in memory of the original HeroRPG (2004–2008). Play in your browser →
Insect Library
A materials-cost calculator and photo library for insect taxidermy — butterflies, beetles and more — with end products and a webshop in the works. Open the app →
Taxidermy portfolio
A public showcase of finished insect taxidermy — butterflies, insects and other pieces — as a preview of the coming webshop. View the gallery →
Prototypes
Rough proofs of concept — the fastest way from an idea to something I can actually poke at.
Write-ups
Notes on what worked, what didn't, and what I learned along the way.
AI Lab
Experimenting with what these models can (and can't) do.
Agents & tools
Wiring language models up to real tools and seeing how far autonomy can go.
Model tinkering
Prompting, fine-tuning, and testing the edges of what current AI is good at.
Ideas in progress
Half-formed experiments that might turn into something — or teach me why they won't.
About
I'm Tjerk Spijkman. I use this space to explore ideas outside of any deadline or roadmap — purely for curiosity and craft. Expect it to change often as projects come and go. If something here is interesting to you, that's a bonus; mostly, it's a place for me to keep experimenting.