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

ExecutionException

The checked exception Future.get throws when the task failed; the real exception is its cause.

java.util.concurrent.ExecutionException wraps the throwable a task threw; getCause() returns it.