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Gold1400

System Design

The Netflix Streaming Architecture

Adaptive bitrate plus edge caches keep video smooth across shaky networks.

5 min read · core · beat Gold to climb

Pre encode everything

Netflix does not transcode on demand. Each title is encoded ahead of time into many bitrate ladders and split into small chunks of a few seconds. This pushes expensive work offline and makes delivery a simple file fetch.

Open Connect at the edge

Netflix places its own caching appliances, called Open Connect, inside internet provider networks. Popular titles are pre positioned close to viewers, so most bytes never traverse the public backbone.

  • Encoding pipeline produces multiple quality renditions per title
  • Open Connect appliances cache popular content near users
  • The control plane picks which appliance serves a stream

Adaptive bitrate

The player measures throughput and buffer health, then requests the next chunk at a bitrate it can sustain. When the network dips, it steps down to a lower rendition rather than stalling.

Smoothness comes from chunked, pre encoded video plus a client that adapts quality continuously.

Key idea

Encode every title offline into chunked bitrate ladders, cache popular content at the edge, and let the player adapt bitrate to current network conditions.

Check yourself

Answer to earn rating on the learn ladder.

1. Why does Netflix pre encode titles into many bitrate renditions?

2. What is the role of Open Connect appliances?

3. How does adaptive bitrate prevent stalling on a weak network?