3. Why we still suck have problems
Since Jan 2013:
Per user, per day:
Photos posted up
20%
Messages up 33%
Time spent up 25%
• 360 million users every month
• 200 million every day
• Feature surpass desktop web
Photo uploads
quadrupled
4. How can we not?
Emerging markets
40% of users still on Gingerbread or earlier
8 million users per day on Froyo
40% of users using old versions of the app
5. What we’ve achieved
Since January 2013:
20-30 new features per month
Crashes per user down 30%
APK size flat
Data usage flat
8. Don’t
HTML5 doesn’t work
New Zealand is your friend
TechCrunch is not
Java on Dalvik is different
Beware server-side libraries like Guava
Purgeable bitmaps don’t help much
9. LinearAlloc
Dalvik loads metadata about each method into a fixed
5 MB buffer
We filled it up (bug fixed in HC)
We hacked into Dalvik’s memory space to increase
this size!
Tested across dozens of devices
10. What four lines can do
4-line change removed some extra data from logging
Reduced start time for FB Messenger by 10%
Ends up saving a year every day!
11. Bitmaps
Use up mountains of memory
Not garbage collected effectively GB and earlier
Leading cause of OutOfMemoryErrors
Rotating, resizing etc, loses purgeability