Why speed is something developers should be in charge of? Product people rarely know what to ask “Can you make this faster?” Invest in speed, It’s one of the best things to spend your time on.

1. BOOM Performance

2. About me …
Co-founded & R&D Manager @
Co-founder & CTO @
eranz@dapulse.com

3. So… what is
BOOM Performance?

4. Fast
Super Fast
Super Duper Fast
BOOM
Boom Speed is the time it takes to say “Boom”

5. 0-100ms
100-300ms
300-1000ms
1000ms
10,000ms
Let’s put it in numbers:
INSTANT (BOOM)
Small perceptible delay
Machine is working
Likely mental context switch
Doesn’t work?

6. Why is
Boom Important?

7. Speed affects your product and the
happiness of your users.
And trust me -
You don’t know when they suffer.

8. Boom Speed = More Usage
Fast:Super Fast:Boom:

9. Boom Speed = Simpler UI
When your UI is slow users will ask you for features
that will make your UI more condensed.
- This will make your product worse.
“Can you add the edit button on the main
project list page? It will be faster to edit projects
this way”

10. No Boom = No Addiction
I use it for
everything
I use it because it
solves a pain
Damn them for
making me use this
shi#$%#
Boom
Fast Enough
Not Fast Enough

11. Invest in speed
It’s one of the best things
to spend your time on.
New killer feature: Serve 10% of users
Boom Performance: Serve 100% of users

12. Why speed is something
developers should be in charge of?
Product people rarely know what to ask
“Can you make this faster?”

13. BOOM Performance
How to achieve

14. The Basics

15. The Basics – Checklist
 Minify JS + CSS
 Gzip compression
 Optimize images (PNG)
 CDN
 Prioritize visible content (CSS / JS)
 Remove render-blocking JS (Move to bottom of HTML)

16. Don’t shoot yourself in the foot
for (var i=0; i < posts.length; i++) {
...
}
$('#item').css('color', '#123456');
$('#item').html('hello');
$('#item').css('background-color', '#ffffff');
var x = $(“.post_wrapper > .reply”).data();
// you could use this instead
$('#item').css('color', '#123456').html('hello').css('background', '#ffffff');
// or even
var $item = $('#item');
$item.css('color', '#123456');
$item.html('hello');
$item.css('background-color', '#ffffff');

17. Things that make the DOM Heavy
• Use with caution:
Round Corners, Box Shadows, Opacity
• Beware of binding scroll callback events
• Avoid using too many elements
(especially in repeatable elements)
• GPU Rendering - Translate3d(0,0,0) / TranslateZ(0)
<div>
<div>
<span><a href></a></span>
</div>
</div>
Always keep 60fps scroll performance

18. CPU Rendering GPU Rendering
.mover {
background: url("particle.png");
height: 100px;
width: 100px;
position: absolute;
-webkit-transform: translate3d(0,0,0);
}
.mover {
background: url("particle.png");
height: 100px;
width: 100px;
position: absolute;
}
Vs.

19. Optimistic Actions

20. Instagram Example
Instagram starts uploading
here
Most apps start uploading
here

21. Facebook Example

23. // Make AJAX request to create post for user
$.ajax("/user/post", {
type: "POST”,
data: { from_date: this.from_date },
dataType: "json”,
success: function(data) {
},
error: function(data) {
// Notify the user on error
...
...
}
});
// Render new post in the UI
... ... ...
... ...
Don’t wait for success. Operate

24. daPulse - Signup Example
[GET] check_sub_domain/a
[GET] check_sub_domain/ab
[GET] check_sub_domain/abc
abc

25. • If you know the expected result in the client
(adding a user to a list, writing a reply, liking a comment, deleting an object, etc…):
Assume it worked and render it BOOM fast in the UI.
• Most of the time, if it fails, don’t do anything (or rollback
to previous state).
Think Positive

26. Action Prediction
prefetch, preload, predict

27. <link rel="prefetch" href="http://dapulse.com/dapulse.js />
Prefetch & Preload
<link rel="prerender" href="http://example.org/index.html">
<link rel="preconnect" href="//www.example.com”>
1. Prefetch (CSS / JS from your homepage)
2. Prerender (Loads entire web page – html, css, js)
3. Preconnect (Opens TCP Connection)

28. Your users are predictable
They will do the same searches & selections 80% of the time.

29.  Track what your users are searching or selecting.
 Preload that into the client.
 Assume “history will repeat itself” and render it
fast in the UI.
 Achieve user happiness :)
Predict your users. How?

30. Provide results from the client

31. Client side libraries
• Typeahead.js – Strong client side search / autocomplete.
• Lunr.js – Powerful client-side Solr / ElasticSearch alternative.
• Localstorage is your friend
– Draft saving
– Result caching

32. The fastest request is “no request”
(a wise man)

33. Perceived Performance

34. Credit: http://blog.teamtreehouse.com/perceived-performance

38. Perceived Speed Improvement
• Gradual UI loading
• Progress bars
• Buttons hover + active state + ladda.js
• Animations
(but don’t animate for more than 100ms)

39. daPulse
Boards case study

42. We’ve tried
 Ajax request + server side caching
 Client side pagination
 TranslateZ (0,0,0) – bad decision
 Reduce HTML elements
 Gradual Rendering
<div>
<div>
<span><a href=“”></a></span>
</div>
</div>
<div>
<a href=“”></a>
</div>

44. Takeaways

45. Takeaways
1. Boom Performance = User happiness.
2. Don’t skip the basic optimization stuff.
3. Unless you must wait for the server – don’t!
4. Fetch the data just before the user needs it.
5. If you can’t make it – fake it (perceived performance).

46. Thank you!
eranz@dapulse.com

47. BOOM PERFORMANCE!
eranz@dapulse.com