JavaScript Intermediate: Write Code That Doesn't Fall Apart When the Data Changes

This is for people who can already make a page react with JavaScript and now need code that survives real projects: Node and npm, modules, classes, real data, waiting for APIs, and tests. You will set up projects that install the same way on every machine, split code into files other people can read, handle JSON and dates without losing data or a day, and prove your code works before a customer finds out it doesn't. If you skip this level, your code works on your machine with your sample data, and breaks the first time the data changes.