JavaScript only does one thing at a time, yet it never seems to wait. In this post, we'll step through the event loop one tick at a time to see how it juggles timers, promises and your code.

Objects, dictionaries, maps — they all find your value almost instantly, no matter how much you store. Let's build a hash map from scratch and find out how.

Binary search is famously simple and famously easy to get wrong. In this post, we'll play with the algorithm until the off-by-one errors have nowhere left to hide.

You press Enter and a page appears. Between those two moments, your browser talks to half a dozen machines. Let's follow a single request from the address bar to the first pixel.