Let's say you're running a podcast hosting platform, or a social network. A user uploads a 40-minute interview in uncompressed format (WAV).
Before anyone can hear it, your app needs four things that did not exist a second ago:
a 30-second preview for the feed,
waveform data so the player can draw something,
transcoded variants in Opus, MP3, etc.,
and the whole thing loudness-normalised, because half of what people upload is recorded too quiet (or too loud).
None of that i...