learn by doing

Practice like it's production — without the risk.

Every challenge is an isolated sandbox. You fix real bugs, review real PRs, and write real tests. Nothing leaves the playground.

Points, streaks and a place on the board. Sign in to start counting — progress is tracked from your first completion.

starting line

Your first branch starts here.

6 challenges. Each one drops you into a real repository — no theory, just the workflow. We suggest starting with something gentle.

The load-more button that never stops

Bug Fix15 min

Start first challenge

Not started

Resolve a three-way merge conflict

Two branches both modified the same auth module. Reconcile all three conflicts without dropping either branch's intent — and figure out when neither side is the right answer.

demanding25 min