Learning Paths

Follow a path, not a catalog.

Each path gives you a short sequence of cases with one clear skill outcome per step.

Async Output Basics

Understand why output order does not always match source order.

Fix the promise patterns that cause undefined values, swallowed errors, and batch failures.

See how Node moves work through nextTick, promises, timers, I/O, check callbacks, and workers.

Recognize references that keep memory alive and learn how to verify cleanup.

Find whether slowness comes from blocking work, sequential waits, worker pressure, or large data.

Practice explaining output order and runtime behavior clearly.