A structured coding practice platform: a leveled skill tree that always tells you what to solve next, an instant in-browser compiler, and timed contests with live leaderboards.
No separate judge, compiler, and classroom tool to juggle.
Write and run C++, Python, or Java right in the browser, sandboxed and ready in seconds.
Try it now →Problems are organized into a prerequisite tree across 21 levels, so you always know what to solve next instead of guessing.
Solve original problems or ones mirrored from CSES, AtCoder, and eOlymp — submitted and judged in the same place.
Timed contests with scheduled-start countdowns, optional passwords, and a leaderboard you can hide until the end.
Teachers and team leads can group learners into a cohort and track how the whole group is progressing.
A dedicated desktop app locks down the exam environment for proctored tests.
Download the exam app →Create a free account and pick up your first problem in under a minute.
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