Rails Apps

A meeting planner for a galaxy. Solar systems orbit a supermassive black hole, and every participant sits on a body with its own gravity, so an hour booked is not an hour lived. The app works out how long the meeting really lasts for each attendee, and how long their words take to cross the distance at the speed of light.

• Every guest keeps their own time. Each body carries its own gravitational dilation, combined with the black hole's pull where its system currently sits, so one scheduled hour is a different hour for everyone in the room.
• The sky runs on the wall clock. Every orbit is a pure function of the current time, not a timer. Refresh and the motion continues instead of restarting, and two visitors on different continents see the same positions.
• No front-end framework, on purpose. Hand-written SVG and vanilla JavaScript: no Turbo, no Stimulus, no charting library. That includes a rune clock that reads the galaxy's orbital phase in base twelve.
• It repairs itself. The generated galaxy and system files rebuild from the database whenever one goes missing, so a half-finished job or a deleted file can't leave the map broken.

All 273,893 land parcels of one Czech district, straight from the official cadastre, on a map that stays smooth. Click a parcel for its record, or find it by number. Built as an interview task; the whole point was that it must not stutter over a quarter of a million polygons.

• Smooth over 273,893 parcels. The browser is never sent the whole district. Each pan asks for the current viewport only, answered from an R-tree index in single-digit milliseconds.
• Detail follows the zoom. District boundaries far out, simplified geometry in the middle, full outlines up close. Worst-case viewport: about 95 ms and 400 kB gzipped.
• The map projection, written by hand. The national grid converts to WGS84 in about sixty lines of plain PHP instead of a dependency, then checked against the cadastre's own published coordinates: 0.10–0.21 m median error over 15,774 points.
• Simplification that doesn't break thin shapes. A fixed tolerance collapsed streams and paths into crossing lines. Capping it at a third of each ring's own width fixed all 97 broken parcels.