A live World Cup prediction map, shipped in a week with Cursor and Claude
Every visitor picks a World Cup winner, and countries light up by majority vote. When the live dot layer choked on mobile, they rewrote it in WebGL to keep it smooth.
Done withCursorClaude✓ Verified· by HN user jonesai· Oct 16, 2026
Result Seeded with 4,200 predictions across 183 nations
“The live dot overlay started out as Canvas 2D, but it choked on mobile once the draw count climbed, so I rewrote it in raw WebGL with additive blending.”
Verified: these results were checked against evidence by Agents in the Wild.
What they did
Over about a week, they built a site where every visitor picks a team to win the 2026 World Cup and makes individual match predictions, coloring each country by its majority pick and ranking nations on a leaderboard by prediction accuracy. They leaned heavily on Cursor and Claude for the code. They also seeded the map with 4,200 predictions across 183 nations before launch, weighted by bookmaker odds, so it would not look empty to the first visitors.
How it went
The live dot overlay started out as Canvas 2D but choked on mobile once the number of dots grew, so they rewrote it in raw WebGL with additive blending to keep it smooth. They also had to switch map boundary data after their original base map merged the UK into a single region.
Try it yourself with Cursor
Pair with an AI coding assistant to build and ship a small interactive web app end to end: describe the concept, have it scaffold the stack, and when a part of the UI chokes under real load, such as a Canvas animation slowing down on mobile, ask it to rewrite that piece in a faster approach like WebGL.
A starting prompt written by Agents in the Wild. Fill in the [brackets], and check what the agent does before it sends, pays for or deletes anything.
After $45 in GitHub Actions overage in one month, a solo founder put an idle homelab to work as CI runners, with Claude making it easy to set up. Daily spend dropped from $2-4 a day to under $0.25.
A first homemade synth has 36 hall-effect keys and buttons and 7 rotary encoders. The firmware started by hand, then gentle prodding at Claude got everything needed much faster. Rev 2 of the PCB is nearly done.
Working on a Quake project, Claude decided on its own to build a test suite: demo playbacks with snapshots compared pixel by pixel, plus recorded demos whose screenshots it checked for each element.
A data scientist tried Cursor on a real project. Prototyping, code completion and commenting went well, but pandas code kept failing and it deleted a bunch of data files.
After building a minimal proof assistant, the writer asked Claude how they knew the prover was actually sound. Claude checked, found five different ways it could prove false theorems, and fixed them.
Four years after shelving a homemade RSS reader and selling off its $500 domain, the writer built it this year with Codex and Claude. They use it daily, along with 30 other strangers who found it public.