Coding practice

This is coding practice for people who already ship software: a fast-track refresher, not a beginner bootcamp. Work through short coding exercises on collections, sorting, hash structures, and algorithm patterns.

Work through it once. Come back whenever you feel rusty. Reset a language any time and run it again.

How the system works

Checklist (left). The course is a sectioned checklist. Open a section, pick a lesson. A check appears only when you've demonstrated the skill, not when you've merely read the notes.

Lesson + editor (center). Each lesson has a short explanation and a real exercise. Write code in the editor and hit Run tests. Your code executes in a sandbox against actual test cases.

AI Assistant (right). Talk through the lesson like you would with a sharp colleague. It can see your current editor code and your latest test results.

• Chat normally to learn interactively.
• /hint: a nudge without the full answer.
• /answer: the solution, walked through.

What you can do

• Switch languages any time: TypeScript, JavaScript, Python, Java, or Go. Progress is tracked per language.
• First half is free. Subscribe when you want the rest of the course, plus the advanced modules generated after you finish.
• Generated topics. Hit 100% on a language and the next module is created for you. Modules are generated rather than static to keep us sharp on our fundamentals!
• Reset progress at the bottom of this sidebar if you want a clean slate.

Open the next section when you're ready to start.