CHAPTER 4 Culture of Performance
vote and comment on it and those votes and comments will get pushed to
the actual poll once it’s been uploaded.
In the background, Polar uploads the temporary copy to its servers. If
that fails, they try again a few times before finally admitting defeat to the
user. The result, once again, is that the process feels incredibly fast.
It’s important to note that for both Instagram and Polar, these solutions
are not exactly ideal from an engineering perspective: there’s quite a bit
more complexity involved. But the trade-off is that the users get a system
that feels instantaneous.adaptively Preload Content
The next secret is to adaptively preload content. This doesn’t mean blindly
load anything and everything you can before it’s needed. Instead, you need
to consider what you know about user behavior and selectively load based
on that. Instagram uses this technique for their photo feeds.
At first, they loaded everything in the order it appears on the page, as
the browser does. But this wasn’t always the best approach because that’s
not necessarily a correct ranking of importance for the user. Instead,
Instagram chose to reprioritize loading based on where the user ended up
scrolling to, using their interests to prioritize what got loaded first.Move bits when no one is watching
Have you ever seen a magician perform? The tricks they do are based on
illusion and distraction. Grand gestures and flashy effects misdirect you
from the sleight of hand taking place right in front of you.
You can perform the same sort of trick to provide an improved expe-
rience for your visitors. In his presentation, Mike demonstrated one way
you can apply this sort of approach.
When users sign up for Instagram, they are asked to fill out some basic
details. While this is going on, in the background Instagram starts looking
for recommendations on who to follow.