Playback clients fetch manifests and media segments, ideally from a nearby CDN edge. Segment caching can reduce origin load dramatically, but authorization and cache-key design must be correct for private videos. Signed cookies or URLs can provide temporary access.

Measure startup delay, rebuffering ratio, playback errors, bitrate selection, CDN hit ratio, and origin egress. View counts should be defined carefully: a play request, a started stream, and a qualified watch are different metrics. Analytics events can be batched asynchronously.

Video cost is dominated by storage, transcoding, and bandwidth at scale. Apply lifecycle tiers, rendition policies, quotas, deduplication where appropriate, and geographic delivery strategies. Do not optimize only for storage price if retrieval delays damage playback experience.