Every problem is a complete workspace — several files, weighted tests, and an editor built for the platform. Follow official tracks or author problems of your own.
Solutions span several files with a real file tree, the way actual projects are built.
Tabs, file management, zip import and export — everything runs in the browser with no setup.
Run sample tests while you work and see exactly which cases pass and where your solution breaks.
Teachers and creators build complete problems with a guided editor, from statement to publication.
Create a problemWrite the statement with examples in the languages you want to support.
Provide driver code and a starter workspace for every supported language.
Define test cases with weights and feedback policies that grade every submission.
Release the problem publicly, keep it unlisted, or bundle it into a playlist.
Every statement opens with worked examples and a workspace ready for your first submission.