Read the lessons before you install anything.

Everything marked free is here in full. Pro lessons are listed so you can see what is in them. The coach, the code runner and the animations are in the app.

• C from zeroA full beginner course with exercises.All 64 lessons free
• Python from zeroA full beginner course with exercises.All 46 lessons free
• Data structures and algorithmsFrom complexity to dynamic programming.15 of 130 lessons free Pro
• System designThe building blocks and worked case studies.5 of 78 lessons free Pro
• AI and MLFrom what an LLM is to RAG, agents and the maths.8 of 67 lessons free Pro
• Design patterns and low-level designSOLID, the 23 patterns, smells and refactoring.All 58 lessons free