Learn by doing

Learn anything.
Make it stick.
Run it for real.

Contest patterns, the structures holding up production systems, PyTorch and CUDA and the guts of an LLM — ordered tracks, editorials that explain the why, and a judge that runs full programs on stdin.

  • 28 pattern tracks
  • 460+ problems
  • 2 languages
  • stdin browser judge

Three ways in

Pick a track and start where you are.

Every entry point uses the same judge and the same editor. Progress on one, and the patterns carry over to the others.

Ready when you are

Start with one problem.

No signup wall. Pick a category, read the editorial, write a full program, and run it against the test cases in your browser.