Yes and yes: you can immediately seek wherever you want. If it's the first time a rendition has been watched, and if we haven't chosen to pre-encode the later segments (which we do sometimes), you might see a slightly longer seek time as we create the first segment after seek, but the difference is marginal and goes away on second view.
> It's interesting your customers want the video immediately
Yep. Some do, some don't. User-uploaded workflows usually care about this; imagine uploading a video to post to a social network and then waiting 20 minutes for the post to go live. (News and sports care about fast publishing too.) Premium media usually doesn't; if you spend a few hours recording a lecture or a yoga class, you don't care if it takes 10 seconds or 10 minutes to publish.
> How long did it take you guys to prove that design out?
You don't want to know. It wasn't easy. The biggest challenge is the ongoing tax; other additions to our transcoding layer have an added degree of complexity. But it's been absolutely worth it for us.
First, it does save money. A meaningful percentage of videos on the internet are never watched in the first place, and an even larger percentage are watched soon after upload and never watched again. We're able to prune unwatched renditions, and if they happen to be requested years later, they're still playable. Transcoding on the fly lets us save both CPU and storage.
Second, it is ridiculously fast. Our median time-to-publish for a 5-20 minute video is 9 seconds. We had a customer (God bless them) complaining a few months ago that it took us something like 40 seconds to transcode a 40 minute video, which actually was slower than normal for us. If you do an async transcode up front, you're looking at 20 minutes, not <1 minute.
> It's interesting your customers want the video immediately
Yep. Some do, some don't. User-uploaded workflows usually care about this; imagine uploading a video to post to a social network and then waiting 20 minutes for the post to go live. (News and sports care about fast publishing too.) Premium media usually doesn't; if you spend a few hours recording a lecture or a yoga class, you don't care if it takes 10 seconds or 10 minutes to publish.
> How long did it take you guys to prove that design out?
You don't want to know. It wasn't easy. The biggest challenge is the ongoing tax; other additions to our transcoding layer have an added degree of complexity. But it's been absolutely worth it for us.