Wait, wait, wait...not forever!

I admit it: I'm in love with my iPhone 6s. It's awesome. I'm having a hard time putting it aside. But recently I feel like it's putting me aside: Since I got my 6s and iOS9 on it, apps have been sluggish: I could be navigating to the next meeting, trying to check my to-do list, grab seats for my next flight and so on. Got me thinking..through my week I go through multiple environments: The WiFi at home/work is near-perfect, vs. cellular network in some places is virtually non-existent. The load on the device could go from very high as I watch my new company video (which I love, BTW) or right after I kill most of the background apps on my phone. What's interesting is, whether I'm mission-driven, like trying to get the boarding pass to get on the plane, or whether in leisure, I'm trying to watch a video or flick through Facebook, I'm increasingly impatient to sluggish apps. So what's going on? Took some Googling, and the answer is right there: iOS9 seems to have some performance issues that are fairly user-visible.  

Interesting timing, as we just launched what we call "The WindTunnel": a way to test your application in the presence of your end user conditions. Only that you don't need the user, it's in the lab, so you can repeat the test nightly. So as soon as iOS9 comes out, all you need to do is update the device and find that it takes YouTube over 12 seconds to launch in some cases. 

Take a closer look and you'll find the YouTube native app CPU is skyrocketed to 54%.

This isn't necessarily the app's doing as much as it's how the app is impacted by the OS. Go back to iOS8.4 and repeat the test across several apps, you'll find a difference across the device/OS/app vitals.

The next question in my mind was, ok, so what would I do about this if I'm a developer of the app, or maybe the app owner. Well, first, this is good to know, and if you have friends in Apple, they may want to know as well. Being told by your end users your app sucks is not great. But that's sort of "Brush your teeth" advice. What would I actually do about it?

Well, it turns your can do quite a bit about it. If you can analyze what's really blocking you, there are several optimizations you can apply. If the app launch time is impacted, reduce the content you pull from the backend(s) on launch towards a balance between cached content and later loading. You may also want to apply better control of the content downloaded and rendered. Some websites are downloading and rendering content to later be pushed down as new content arrives (typically ads, annoyingly enough). Specifically when it comes to responsive web pages, there's a lot of room for improvement both from a content perspective as well as techniques. It turns a lot of images downloaded belong in the PC-high definition display and not on a mobile device. Let's leave that for another post. 

So, what's your perspective on this? Have you experienced this yourself and how are you addressing this (if you're an app owner or developer)?