1.
U S I N G
H E AT M A P S
T O D E F I N E
P E R F O R M A N C E
M E T R I C S
S E R G E Y C H E R N Y S H E V
O R G A N I Z E R , N E W Y O R K
W E B P E R F O R M A N C E M E E T U P

2.
W H Y D O W E M E A S U R E S P E E D ?
• Monitor for degradations (Ops)
• Analyze code for perf issues (Devs)
• Verify improvements (Devs)
• Prioritize improvements (Business)
• Budget for WPO initiatives (Business)

3.
T O D AY ' S M E T R I C S
• DNS, SSL/TLS, TTFB
• Page Load / Document Complete / Fully Loaded
• First Paint
• AFT
• SpeedIndex

4.
M E A S U R E U S E R E X P E R I E N C E
• Good experience for users
• "Fast" is just a component
• Do not measure what's
easy - measure what
matters.
N O T T E C H N O L O G Y

5.
T I M E T O F I R S T PA I N T
• Shows when completely useless part is over
TTFP
3.5s

6.
A F T ( A B O V E T H E F O L D T I M E )
• When everything is finally visible
AFT
15.3s

7.
S P E E D I N D E X
• Unifies rendering progress in one number
Speed Index
8618

8.
U S E R T I M I N G A P I
• Records custom JS timings on the page
• Measured by both RUM and Synthetic tools
• Can be hard to match with user's reality
• Requires JavaScript instrumentation

9.
H E AT
M A P S
D I S C O V E R A N D
D E F I N E
W H AT M AT T E R S
U S I N G

10.
U S E R A C T I O N H E AT M A P S
• Eye tracking
• Click tracking
• Hard to capture
• Shows current state,
not the intent for
new features
• Can be automated

11.
P R O D U C T F E AT U R E H E AT M A P S
• Hard to automate
• Each industry is different
• Usually multiple
templates that power
many pages
• Good news - business
team already knows the
answers

12.
I N T E R A C T I O N O N T H E W E B
1. Acknowledge action
2. Verify destination
3. Provide primary content
4. Allow interaction
5. Show secondary content
6. Invisible tasks

13.
D E S I G N C O M P O N E N T S
• Core Branding &
Main Navigation
• Primary content

14.
H E AT M A P C U T- O U T S
Core Branding & Main Navigation Primary content

15.
C O R E B R A N D I N G H E AT M A P
Core Branding & Main Navigation
8s

16.
P R I M A RY C O N T E N T H E AT M A P
11s
Primary Content

17.
E X T E N D E D M E T R I C S
• Time To First Paint (TTFP) - 3.5s
• Core Branding & Main Navigation - 8s
• Primary content - 11s
• ...
• Above The Fold (AFT) - 15.3s

18.
S E L E C T O R - B A S E D I M P L E M E N TAT I O N
• Uses CSS selectors to define active zones
• Executes "custom metric" function in WebPageTest to
get cutout coordinates
• Downloads test results and video frames using WPT API
• Manipulates video frames and feeds into
visualmetrics.py and uses 99% threshold to grab times
• Kudos to Patrick Meenan for awesome tools

19.
T H A N K Y O U !
sergey.chernyshev@gmail.com
@SergeyChe