Learn Python asyncio from zero by building the event loop by hand. Six fetches go from 12 seconds to 3 on one thread, and you understand every line. Most asyncio tutorials throw async and await at you on page one. This course builds the event loop by hand first, in plain Python, so the keywords finally click. Six fetches drop from 12 seconds to 3, on one thread, and you understand every line. No magic. This interactive course has a companion book, Asyncio Without the Magic, on Leanpub at https://leanpub.com/asyncio . The book is the deep, cover-to-cover read; the course is where you make it stick with quizzes, build-it-yourself exercises, and runnable notebooks. They are built to be used together: read the idea in the book, then drill it in the course until it is yours. You get a lot from either one on its own, and the most by far from both together.