Backend engineer in Kraków. People say I've turned into a cyborg. I only work 32 hours a day.
Hi, I'm Andrzej - a developer by training and by choice, and a teacher by inclination. Java and Spring pay the bills at Sanoma Learning. For six and a half years before that, evenings and weekends went to Software Development Academy, walking people through their first working program.
The rest of the time goes into the projects below: Android and iOS, a family of Minecraft server plugins, browser extensions, and whatever I have decided to learn next. When none of that is happening, I'm on a motorcycle or behind the wheel, and working toward a driving instructor license - the teaching habit, back on the road this time.
Every day carries an odd little holiday, and Ferrio tells you which. Android since 2014, iOS in SwiftUI, and the web - all fed by one API. The holidays live on a server rather than inside the app, so a correction or a new entry reaches everybody without waiting for a store review.
Plugins for Paper servers, rebuilt in 2026 from a line of Spigot plugins I started in 2014. The rewrite kept the ideas and dropped the rest: the prefix, the in-house command library and the plugins nobody needed anymore.
Select text, type a bracket, and the text ends up inside it instead of being replaced. What every code editor does, in every input on any page. Editors have had the habit for twenty years and no browser does it anywhere else; this teaches it to Chrome, Edge and Firefox.
A daily guessing game with one rule: a single pixel is hidden on a board of ten thousand squares, and every player in the world gets one guess at it per day. No hints. The answer is revealed the next day, and a new area takes its place.
A treasure hunt played on foot. Follow a trail of clues through a real city, reach each spot on real GPS to unlock the next one, and solve the puzzles hidden along the way. Anyone can build a trail of their own and publish it or share it privately.
A word puzzle for Android that never shows you the words, only their lengths. Each one snakes through the grid of letters, and together they cover every square exactly once. A solver checks every board before it ships, so there is always exactly one answer.
