Challenge-first design — You start with code that puzzles you, not code that teaches you.
It supports layered explanations — Every solved challenge reveals the deeper mental model behind closures, step by step.
It has Instant feedback — A live code environment that responds to every tweak, so you learn by doing, not guessing.
It is built for real devs — The problems aren’t classroom examples; they’re the ones that trip up even senior engineers in production.
KoomeK•2h ago
Challenge-first design — You start with code that puzzles you, not code that teaches you.
It supports layered explanations — Every solved challenge reveals the deeper mental model behind closures, step by step.
It has Instant feedback — A live code environment that responds to every tweak, so you learn by doing, not guessing.
It is built for real devs — The problems aren’t classroom examples; they’re the ones that trip up even senior engineers in production.