1.
@tameverts
#WebPerfDays
How to create a
performance-first culture

2.
@tameverts
WPOstats.com

3.
2009 Cut average load time from 6s to 1.2s
7-12% increase in conversion rate + 25% increase in PVs
Average load time increased to 5s
User feedback: “I will not come back to this site again.”
Re-focused on performance
0.4% increase in conversion rate
2010
2011
@tameverts #WebPerfDays

4.
1. No front-end measurement
2. Constant feature development
3. Badly implemented third-parties
4. Waiting too long to tackle
performance problems

5.
During a performance
optimization sprint

6.
After a performance
optimization sprint

7.
Everyone who touches
a page should care
about the performance
of that page.

8.
Identify what people
care about

9.
❑ bounce rate
❑ cart size
❑ conversions
❑ revenue
❑ time on site
What do people care about?
#WebPerfDays@tameverts
❑ page views
❑ search traffic
❑ user satisfaction
❑ user retention
❑ ???

10.
Who they are What they care about What to show them
Executives
Competition
Business impact
Benchmarks (filmstrips and videos)
Correlation charts (perf + KPIs)
Marketing
Third parties
Traffic + engagement
SEO
Third-party performance
Correlation charts (perf + bounce rate)
Lighthouse SEO audits
Devs / engineers Well, lots of stuff, probably Consult with perf team
@tameverts #WebPerfDays

11.
BBC loses an additional 10% of users for every
additional second it takes their site to load
Ancestry.com saw a 7% increase in conversions
after improving load time by 64%
FT.com reduced desktop load times to 1.5s and
mobile to 2.1s and increased user engagement
by 30%
@tameverts #WebPerfDays

12.
Fire up people’s
competitive spirit

13.
Collaborate on
performance budgets

14.
Thresholds YOU create for metrics
that are meaningful for YOUR site
https://addyosmani.com/blog/performance-budgets/
Milestone timings (e.g. start render)
Quantity-based (e.g. image weight)
Rules-based (e.g. Lighthouse scores)

15.
A good performance budget
should show you…
What your budget is
When you go out of bounds
How long you’re out of bounds
When you’re back within budget

16.
Who What Metric
Ops Back-end issues TTFB
Marketing
Most important content
Third parties
SEO
Hero rendering times
Custom metrics
Lighthouse SEO score
Devs / engineers
How well page is built
Performance issues
Start Render, Speed Index
Lighthouse Performance score
@tameverts #WebPerfDays

17.
Give people ownership over their
performance budgets.
Make sure they get alerts when
their budgets are exceeded.

18.
Share just
the right amount

19.
How often is often enough?
Wall monitors and dashboards 24/7
Alerts in realtime (to people who can make fixes)
Reports no more than 1X week

20.
Score some easy wins

21.
“The dull boring stuff”
~Andy Davies
Scripts (especially third parties)
Images
Unneeded code
Deferring assets where possible

22.
issue 1
image quality and
compression
issue 2
image sprite blocking
page load

23.
2-second improvement
in median page load time
almost doubled mobile conversions

24.
Don’t forget
to celebrate!

25.
#ring_the_bell

26.
thanks!
@tameverts
speedcurve.com/blog