Real problems. Your solution.
A blog that writes itself every morning from a list of feeds, with every claim linked to its source — and a kill switch for the days it gets something wrong.
A community board stores precise coordinates and is supposed to show only a coarse grid cell. A user found that sorting by distance from two different points lets you triangulate anyone's house. Fix it properly.
Not a blocker — a negotiation. A kid proposes, a parent counter-proposes, and an agreement becomes a schedule both can see.
Someone needs a ladder; someone three streets away has one. Build the board, keep it local, and keep it safe.
A message board that a device with 320 KB of RAM can read and post to. No JavaScript required, no cookies, and it still has to handle abuse.
Fifty agents with published positions debate a proposed amendment and vote. Build the simulation, make the debate readable, and make the result reproducible.
Two halves, a wireless link, layers, and a battery that lasts. Build the keymap engine and a simulator; flash to real hardware if you have it.
A QR code you can hold. Text in, a raised-module STL out, and it must actually scan when printed.
Stepper motors sing if you drive them at the right frequency. Turn a MIDI file into G-code that plays it on a printer's three axes — safely.
Drawer organisers on a 42 mm grid. Build a planner: draw the drawer, drop bins in, get a shopping list and the STLs.
Convert an image into layered heightmaps for a multi-colour 3D print, so a photo becomes a backlit panel.
Draw or import line art, then drive a plotter — in one browser tab. Build the path planner and the G-code, with a simulator so no plotter is needed.
Someone photographed a pencil sketch of a pegboard layout and got a print file back. Build that: a photo of a sketch in, a valid STL out.
A two-player browser game in the repo goes out of sync after about a minute: the players see different boards. The netcode is small. Find the cause and make it deterministic.
"Who or what is it?" — a picture, four options. The hard part is the pool: hundreds of questions, difficulty that adapts, and a promise that a player never sees the same one twice.
A creature that lives on a 128×64 screen, needs things, and remembers you were gone. Build it for a simulator first; a real handheld is a stretch.
The repo has the Pascal source of a small 1990 dungeon crawler. Make it run in a browser, faithfully, with the original's feel and none of its crashes.
A page that shows a bar of rhythm notation, plays a click, and grades how accurately you tap it back. Single page, no backend.
A generator that lays out a small theme park — paths, rides, food, queues — under a design system of constraints, and scores the result so you can keep the best one.
Play the drums alone. Then the bass. Then the vocals. How many stems until you name the song? Build the game on top of a stem separator.
An eighteen-year-old site did this with screenshots and a text box. Build the modern version: a still, a guess, a streak — and it must not be trivially cheatable.
A rota app lets a manager approve two swaps that put the same person on overlapping shifts. It only happens when two managers approve at the same moment. The code is in the repo with a test harness that can run approvals concurrently.
A whimsical one: a Home Assistant card that shows a picture of your cat matching the weather — sunglasses on a sunny day, an umbrella in the rain. Build the image pipeline and the card.
A Telegram bot that lists your containers, restarts one, and tells you when something falls over — and cannot be used by anyone but you.
83 challenges available
Results scored by AI. Build with any tools you want.