Santa Tracker - Moving to Android App Bundle

Every year, Google releases the Santa Tracker app to millions of users across the world, wanting to track Santa over the holiday season. Chris will talk through how they managed to get the install APK from 60MB to 10MB, using Dynamic Feature Modules, asset compression and other things.

Transcript

1. Moving to Android App Bundle
   Chris Banes
   @chrisbanes
   

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6. Goals for 2018
   ★ Convert more classes over to
   Kotlin (from 26%)
   ★ Bring our download size to 10MB
   ★ 2017’s APK was 60MB
   

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7. Android App Bundle
   Official Android app publishing format
   Average size savings of ~35%
   Enables dynamic features
   

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8. Deliver only what’s
   needed
   Languages
   Screen density Announced at I/O ‘18
   CPU architecture
   

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9. Base
   App Bundle
   

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10. Base
    xxxhdpi
    xxhdpi
    xhdpi
    hdpi
    mdpi
    ldpi
    App Bundle
    

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11. Base
    xxxhdpi
    xxhdpi
    xhdpi
    hdpi
    mdpi
    ldpi
    x86_64 arm64
    x86 arm
    App Bundle
    

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12. Base
    xxxhdpi
    xxhdpi
    xhdpi
    hdpi
    mdpi
    ldpi
    x86_64 arm64
    x86 arm
    pt
    fr
    en
    de
    zh ja
    App Bundle
    

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13. pt
    Base
    xxxhdpi
    xxhdpi
    xhdpi
    hdpi
    mdpi
    ldpi
    x86_64 arm64
    x86 arm
    fr
    en
    de
    zh ja
    Santa + Samsung Galaxy J5: en, arm, xhdpi
    

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14. Mrs Claus + Pixel: en & fr, arm64, 560dpi
    pt
    Base
    xxxhdpi
    xxhdpi
    xhdpi
    hdpi
    mdpi
    ldpi
    x86_64 arm64
    x86 arm
    fr
    en
    de
    zh ja
    

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15. Mrs Claus + Pixel: en & fr & pt, arm64, 560dpi
    pt
    Base
    xxxhdpi
    xxhdpi
    xhdpi
    hdpi
    mdpi
    ldpi
    x86_64 arm64
    x86 arm
    fr
    en
    de
    zh ja
    

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16. hdpi
    x86_64
    mdpi
    x86_64
    xhdpi
    x86_64
    xxhdpi
    x86_64
    ldpi
    x86_64
    xxxhdpi
    x86_64
    hdpi
    x86
    mdpi
    x86
    xhdpi
    x86
    xxhdpi
    x86
    ldpi
    x86
    xxxhdpi
    x86
    hdpi
    arm_64
    mdpi
    arm_64
    xhdpi
    arm_64
    xxhdpi
    arm_64
    ldpi
    arm_64
    xxxhdpi
    arm_64
    hdpi
    arm
    mdpi
    arm
    xhdpi
    arm
    xxhdpi
    arm
    ldpi
    arm
    xxxhdpi
    arm
    Galaxy Nexus: hdpi, arm. Pre-Lollipop
    

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17. APK
    APK
    Before After (M+)
    Compressed
    native libraries
    Wasted space!
    Uncompressed
    native libraries
    Uncompressed native librariesNew!
    

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18. ▼16%
    size on
    disk
    ▼8%
    download
    size
    Uncompressed native librariesNew!
    * On average
    

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19. Uploading an AAB saved us 20%
    Down to 48.5MB!
    Go try it!
    ./gradlew bundleRelease
    Dynamic delivery
    

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20. ➔ Allow you to split your app into
    separate downloadable modules
    Feature modules
    

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21. package="com.example.santatracker"
    split="elf_jetpack"
    ...>
    
    

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22. package="com.example.santatracker"
    split="elf_jetpack"
    ...>
    dist:title="@string/elf_jetpack_title">
    
    
    

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23. package="com.example.santatracker"
    split="elf_jetpack"
    ...>
    dist:title="@string/elf_jetpack_title"
    dist:onDemand="true">
    
    
    
    

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24. # Dynamic feature module, "elf_jetpack"
    apply plugin: 'com.android.dynamic-feature'
    android {...}
    dependencies {
    implementation project(':base')
    ...
    }
    

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25. # Base module: "base"
    apply plugin: 'com.android.application'
    android {
    dynamicFeatures = [':elf_jetpack']
    ...
    }
    

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26. Google Play
    Servers
    Play Core library
    Responsible for:
    ● Installing on-demand modules
    ● Managing modules
    

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27. ➔ First install == base install
    ➔ Each game == feature module
    Feature modules
    

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29. ➔ All of the game modules were
    coupled and messy
    ➔ Had to spend a lot of time
    breaking them apart
    ➔ Testing is difficult. Need to
    upload to Play Store to test
    What was hard?
    

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30. Internal test track
    Byte-for-byte what Play delivers
    Upload to Play Console and have
    it served immediately to your QA
    team.
    

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31. Wait for
    processing
    Internal test track
    Alpha and Beta tracks
    * After first upload
    

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33. For our final 2018 release...
    Results
    Base install:
    9.21 MB (from 60MB)
    In total, saved roughly:
    42 TB of storage and transfer
    

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34. 85%
    smaller than 2017
    

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35. For more information, we recently
    published a Medium article:
    medium.com/androiddevelopers
    Thanks!
    

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