Free public beta until December 4, 2026: every course is open, no card needed. After that, the first chapter of each course stays free and full access is a one-time $39 ($19 for up to 100 founding members chosen for helpful feedback). Your progress is kept. How the beta works

code review

A teammate reading your changes before they're merged, to catch mistakes and share knowledge.

Code review is the inspection of a change by peers, usually on a pull request, for correctness, clarity, tests and design.