Media streaming is one of the most demanding challenges in distributed systems. It combines massive data volumes (video is heavy), strict timing requirements (frames must arrive on schedule), and highly variable client conditions (networks change constantly).

Get any of these wrong, and your viewers see buffering, stuttering, or pixelated video.

In this chapter, we'll explore how real-time media streaming systems work. These concepts show up in system design interviews for platforms like Netflix, YouTube, Twitch, Zoom, and any application involving video or audio delivery.

Why Is Streaming Challenging?