MAKING YOUR WEBSITE FAST - AND SCALABLE

Deri Jones

Digibury January 2015

Tue Feb 3rd

WEBSITE SPEED Black Friday and Xmas peaks

UNACCEPTABLE DELAYS

THE NEED FOR SPEED Impatience SEO

THE NEED FOR SPEED Impatience SEO UX is the final USP

YourUX

Your offering

What makes sites slow ?

Network effectsADSL 3G 4G

LATENCY

LATENCY TARGETS Backbone best:

Local: ADSL 25 mS Mobile 250 mS

Network effectsBulky: ImagesToo many objectsNot using HTTP Keep alive

FIREBUG / DEVTOOLS

Browser effectsObjects blockRendering time

3RD PARTY SCRIPTS

The offender:<script src="http://3rdparty.com/script.js"></script>

Old solution

These days<script async defer src="siteScript.js" onload="myInit()"></script>

These days:

Browser effectsObjects blockRendering time3rd party blocking

AD SERVING IS SLOW

And no political motive to be fasterWill get slower as big-Data progresses

RESPONSIVE WEBAvoid the Whitehouse.org story...

Can be good:Painless installMany configuration choices

Can be tricky:Embedded CSS obsession

TOOLS Firebug, DevTools HTTPArchive.org Webpagetest.org

DESIGNERS VS SPEEDERS

CHALLENGES Responsive web:

Better than 2 sites www. and m.

WEBSITE SCALING

SURPRISING LESSONS Cloud auto-scaling – doesn't work

SURPRISING LESSONSCloud auto-scaling – doesn't work

Scales too late Allows rest of farm to die Small print: Strictly 'very often' doesn't work

SURPISING LESSONS Cloud auto-scaling – doesn't work

Scales too late Allows rest of farm to die

CLOUD AUTO-SCALING Uncertain spin-up time DOA

SCALING Don't obsess Disk IO

Yes it's moving metal Web is a lot about static content

SCALING The code platforms are good Many problems in SysAdmin configs CDNs

Cache-Miss hurts

But don't assume!

SCALING Many big hosters:

Not motivated to help you

SCALING

USERS' EXPERIENCEIt's both:The new battlegroundA challenge

Single Page website Offline-cache content Users' journeys complexity

USER EXPERIENCE Cultural shift

Make every one responsible for it! Performance is a deliverable

Test every release Continuous Integration

USER EXPERIENCE Hard Easier to save timings in your code

ElasticSearch, Graphite RUM and Analytics help

USER EXPERIENCE 'Do what your Customers do'

more Synthetic monitoring For another day ...

RESOURCES

London Web performance meetup http://www.meetup.com/London-Web-Performance-Group

Third Party Footprints http://www.slideshare.net/bbinto/third-party-footprint-evaluati

ng-the-performance-of-external-scripts HTTP Archive

https://speakerdeck.com/deanohume/the-good-the-bad-and-the-ugly-of-the-http-archive