How is the Netflix app so efficient?

Recorded February 24th 2021 – watch the full episode on YouTube.

‌When you press play in Netflix, usually the content is playing straight away – what secret sauce do you have to get that kind of performance?

Jordanna Kwok: If you look at our App Store reviews, a lot of it is about the content. "One star, you don't have this show, The Office is not on anymore." So I'd rather get that type of one star review than one star review, "Your app is crashing."

That's in our control. So, certainly there's a lot that we do. We want to make it as seamless as possible for Netflix members to playback from anywhere, whatever conditions they're on, whether they are on the subway or something like that, or on 5G. I don't know how many people have 5G now, but there's a lot of backend infrastructure that is at play here, so it's not necessarily completely on the client itself, although we do integrate heavily with a lot of our backend infrastructure to make it so quick.

"It is a combination of a lot of things to make it run this smoothly and the goal really isn't for people to notice how quickly it is. If they don't notice it, perfect, it's working."

If you go to the Netflix tech blog there's going to be tons and tons of articles that you can read, especially if you look up OpenConnect – that's our CDN backbone, essentially. So it is a combination of a lot of things to make it run this smoothly, and the goal really isn't for people to notice how quickly it is. If they don't notice it then perfect – it's working. But if people are recognizing that, “wow, this other service isn't as quick,” then at least we know we've done our job to make it as seamless as possible.

Paul Hudson: When I switch to somewhere else it certainly feels strange seeing an activity indicator because the app is buffering, or when I use an app without a 15-second rewind button. Even today I think QuickTime doesn't have a 15-second rewind button – I'm just tuned to have that button in place for things I missed out on or whatever, it's frustrating when it's not there.

You're setting the standard for the UI of video in some respects – people use it so much now, it is the de facto thing to copy. You are the yardstick, basically, for what makes good mobile UI, which must be a great place to be.

This transcript was recorded as part of Swiftly Speaking. You can watch the full original episode on YouTube, or subscribe to the audio version on Apple Podcasts.

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