Velocity 2016: It's a Wrap!

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VELOCITY 2016 IT'S A WRAP!
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Last week was one of my favorite weeks of the
year. No, not my birthday week. It was OReillys
Velocity Conference in Santa Clara. Ive attended
Velocity five of the last six years, and it is
always a great time. I spent the week
reconnecting with former co-workers and friends,
putting faces with Twitter avatars, and totally
geeking out about web performance. It is always
a struggle for me to choose which sessions to
attend. It seems like there are two or three
sessions I find appealing during every time slot,
not to mention the hallway track conversations
and checking out the new technologies in the
exhibit hall. Below are some talks that piqued
my interest Initial congestion window size On
Tuesday, I attended Tobias Baldaufs tutorial
on HTTP/2 and Hero Images. I was intrigued by his
formula to calculate the best initial congestion
window and the idea that the initial congestion
window size in HTTP/1.1 may result in less than
optimal performance in HTTP/2. The more I thought
about this, the more confused I got. Currently
there is an experimental specification RFC
6298 to increase TCPs initial window to 10, but
Tobias was talking about increasing it to 25. Is
there another proposal forthcoming to propose
changing the max initial congestion window from
10 to 25? Today we are supporting HTTP/1.1 and
HTTP/2. What mechanisms are in place to support
optimal settings for each of these protocols? Or,
are we faced with having sub-optimal performance
for one protocol while we optimize for the other?
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Ad Blockers Lots of conversations and talks
about the impact of browser extensions, in
particular Ad blockers. Bruce Lawson, Deputy CTO
at Opera, gave an excellent keynote, Making bad
ads sad. Rad!, filled with statistics and humor
on the state of advertising on the web. Instart
Logics Karan Kumar presentation on Measuring Ad
Blocker's Impact on Performance provided a
slightly different take on ad blockers, and
reported results from a study on how ad blockers
dont always improve performance. For sites that
are ad heavy, ad blockers can improve performance
but when the site has limited ads, or none,
performance can actually worsen. Im disappointed
I missed the talk from Yoav Weiss on Taking Back
Control over third-party content. I would have
liked to hear how that compared to the other two
talks. I will have to watch the session
replay. Machine Learning Tammy Everts and Pat
Meenan presented Using machine learning to
determine drivers of bounce and conversion. Their
talk raised a lot of questions that need further
exploration, as their results differ from
previous studies and many peoples gut
reactions. One question I had was, why does the
number of scripts impact conversions? I found
myself wondering if pages with fewer scripts
actually had heavier scripts, and if the true
issue was weight of the scripts, not the
number. It was disappointing to hear that metrics
we focus on in terms of perceived user experience
turned out to be relatively meaningless in their
impact on bounce rates and conversions. A large
part of me wants this information to be wrong
perception of page load time has to have an
impact. I may just bury my head in the sand and
pretend I didnt hear that so I can keep talking
about perception and user experience at least
until I see more studies corroborating this.
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• Accessibility
• Estelle Weyl is trying to make the web accessible
  as well as fast. In her Accessibility as
  Performance talk, she illustrated how making a
  site accessible does not mean you have to
  sacrifice performance. On the contrary Estelle
  demonstrated how using semantic HTML can improve
  both accessibility and performance
• There are many talks I wasnt able to attend,
  such as
• The top 10 performance defects that are costing
  you millions
• H2 in the real world
• Understanding the performance penalty HTTP vs
  HTTPS
• Facebook web performance Using data from the
  field
• If you missed Velocity, dont worry there are
  many slides and videos available at
  the conference site, and Andreas Grabner has
  provided the notes he took during keynotes and
  sessions on his blog. I will spend a good portion
  of the coming weeks checking out presentations
  and videos of the sessions I missed because,
  alas, I still dont own a TARDIS.
• Until next year...

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