Apple AppStore App Preview - mov format If we submit the App Preview in the MOV format, will it be compressed on the Apple side to a shorter format (e.g. MPEG4) or will it be streamed to the user as MOV?

In another word, do we have to convert the recorded MOV to MPEG4?

As we all know MOV are very big and not good for streaming.
.mov is a container format that encompasses a variety of codecs. .mov is also a file format, not streaming (which is presumably how video is distributed for the App Store.)

I'm still somewhat unsure of what backend is used by Apple for their video streaming, but I believe they use their own HLS backend, which uses the MPEG-4/H.264.

Note that Apple transcodes whatever you upload, so it doesn't really matter how you upload it–except for possible differences in upload times and whatever additional time is needed on their end to transcode it.