Key features
- Thousands of coding challenges (kata) across 55+ languages
- Difficulty ranking system from 8 kyu (beginner) to 1 kyu (expert)
- In-browser code editor with instant test-driven feedback
Pros
- Massive library of challenges across 55+ languages
- Community solutions teach you patterns you would not discover alone
Cons
- No structured learning paths or curriculum, just individual challenges
- Some kata have unclear instructions or edge cases
