Session recording captures a live class as a video file so that learners who missed the live session or want to review can watch it on demand; it is the bridge between synchronous and asynchronous learning delivery. Recording can happen server-side, where the SFU or a dedicated media recorder mixes tracks centrally, or client-side, where one participant's browser records the composite view — server-side is preferred for reliability and to avoid depending on any single participant's connection. The raw recording typically needs post-processing before publishing: trimming dead time at the start and end, adding chapters that correspond to the session agenda, auto-generating captions via ASR, and transcoding into adaptive-bitrate formats (HLS or DASH) for CDN delivery. A practical complication is compositing: if the instructor shared a screen and ran a whiteboard simultaneously, the recording pipeline must decide how to lay out these inputs in the final video — usually a picture-in-picture or side-by-side layout. Chat and poll data from the session can be burned into a sidecar file and surfaced as interactive overlays in the on-demand player. Watch-time analytics on the recording reveal which parts of the class were most engaging and where learners dropped off, giving the instructor actionable feedback for future sessions. Storage and retention policies must account for the significant file sizes and any data-privacy obligations around participant video.
