sydepsystem design atlas

Video Streaming (Netflix-style)

Transcode once, serve adaptive bitrate streams from the edge.

AdvancedMedia
Master UploadStorageTranscoding PipelineComputeRendition StoreStorageCDNNetworkingPlayerClientCatalog ServiceComputeCatalog MetadataStorageRecommendationsAI / ML

Uploaded masters are transcoded into multiple resolutions/bitrates, stored, and served through a CDN using adaptive bitrate streaming so playback quality adjusts to each viewer's network in real time.

When to use it

  • Large catalog of on-demand video watched by a geographically distributed audience
  • Playback quality needs to adapt automatically to fluctuating client bandwidth

Trade-offs

  • Transcoding a large catalog into many renditions is computationally and storage expensive
  • CDN cache misses on cold/long-tail content still hit origin at full cost

Components used

Object StorageBatch / Scheduled JobCDNDesktop AppManaged App ServiceDocument DatabaseLLM / Model Endpoint

How it works

  • Video is transcoded once into a ladder of resolutions and bitrates, then segmented into small chunks with a manifest describing them.
  • The player measures available bandwidth and requests the next chunk at whichever quality it can sustain, switching mid-stream without interruption.
  • Chunks are served from CDN edges, so the origin serves almost no viewer traffic.

Used in the wild

  • Subscription video-on-demand catalogues.
  • Course and training platforms.
  • Any long-form video where buffering is the primary quality complaint.

Good to know

  • Adaptive bitrate is why video degrades in quality instead of stalling. The player is continuously making a bandwidth bet, one segment at a time.
  • Netflix places its own appliances inside ISP networks so popular content is served from within the ISP entirely. At peak, video streaming is a large share of all consumer internet traffic, and this is how it stays viable.