Multithreading in Node.js always feels to me like I’m beating the system. The whole concept of spawning child_process to parallelize CPU tasks feels like I'm hacking my node.js to be something she is not. Since worker threads officially released in node 12, this is no longer the case. In this lecture I am going to observe and analyze the different behaviors and performances of child_process vs worker_threads and conduct a list of considerations on when to use each. I will demonstrate this on a file-watcher app that integrates with a live-code-player that will blow your mind.