Free public beta until December 4, 2026: every course is open, no card needed. After that, the first chapter of each course stays free and full access is a one-time $39 ($19 for up to 100 founding members chosen for helpful feedback). Your progress is kept. How the beta works

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Bug-Hunt Time Trial

Two minutes. Each function has one bad line: an off-by-one, a stray semicolon, = where == was meant, an integer division. Find it.

⏱️ 120s

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