38M browsers every day
500K concurrent users
Most popular news website in the UK
One of the most popular websites overall in the UK
One of the most popular websites in the world
BBC News
From Bangalore (India) on 3G
The Guardian
From Bangalore (India) on 3G
Identifying Performance Issues
Multivariate Testing
Remove blocking script from <head>
Page renders 1000ms sooner
Only download required CSS
Page renders 1000ms sooner
Don't include unused JS on the page
Page renders 200ms sooner
Load adverts asynchronously
Fixing the Issues
&
Measuring the Results
Async. Adverts
Global CDN
Lazy Load Images
Terminate TLS at Edge
Outstanding Issues
"The Hard Stuff"
765KB of JS
23 HTTP Requests
710KB of CSS
No "critical path" CSS
Technical Debt
BBC News Performance
By Joseph Wynn
