// LEARN
Learn by doing
Short, practical lessons where you answer before you read the explanation, with a focus timer that notices when you drift. Free, and progress saves if you create an account.
Choose a section
- 3 lessonsAITokens, context windows, hallucinations and prompts, through predict-then-check exercises.Explore AI
- 3 lessonsCareersTen growing tech roles with sources, and practical lessons for AI, data and DevOps engineers.Explore Careers
- 240 lessonsLanguages & frameworksJavaScript, SQL, Python, TypeScript, Java, C#, C++, Node.js, React and Next.js, as courses in three levels, written module by module.Explore Languages & frameworks
How a lesson works
- 1.Warm up by recalling what you learned before.
- 2.Predict or decide before any explanation. Being wrong here is useful.
- 3.Practise with a worked example, then on your own.
- 4.Solve one brain teaser that uses the idea in a new way.
- 5.Apply it in a small real task, checked against a rubric.
- 6.Pass the exit ticket (80%) to complete the lesson.
Why this format
Testing yourself and spreading practice over time are the two techniques rated “high utility” in a widely cited review of learning research (Dunlosky et al., 2013). Every lesson is built around them. doi:10.1177/1529100612453266
A focus timer on every lesson
25 minutes of focus and a 5-minute break, with a longer break after four blocks. Leave the tab and the timer pauses; come back and you get a quick recall question to pick up where you were. Everything is adjustable.
Found a mistake?
Every lesson and every activity has a “Report a problem” button. Anyone can use it, no account needed, and each lesson shows the date it was last reviewed.
Save your progress
Lessons work without an account. Create one with an email and password to keep completed lessons, notes and focus time across devices.