Working effectively at scale

Transcript

1. Working e!ectively at scale

2. Francisco Díaz franciscodiaz.cl - @fco_diaz

3. Startups 2011 - 2017

4. Airbnb 2017 - today

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14. organizations ... are constrained to produce designs which are copies

    of the communication structures of these organizations — Conway's law

15. How do you divide your codebase?

16. Architectural layer

17. User Flow

18. What about Airbnb?

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20. 1 million lines of Swift

21. ~80 commits to master on any given day to the

    repo (Android + iOS)

22. Bigger buckets

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24. A user should be able to wishlist a listing from

    the booking flow

25. How do they relate with each other?

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29. 50 min local clean builds

30. ~30 min !

31. Buck HTTP Cache https://github.com/airbnb/BuckSample

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33. ~5 min !

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36. Dependency inversion

37. ‣High-level modules should not depend on low- level modules. Both

    should depend on abstractions. ‣Abstractions should not depend on details. Details (concrete implementations) should depend on abstractions.
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39. A user should be able to wishlist a listing from

    the booking flow
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41. Easy! WishListDataSource + interface!

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43. WishListDataSource is still visible

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45. Socializing best practices

46. !

47. +60 iOS developers

48. Automating best practices

49. Groups Modules

50. Groups Modules Module Types

51. Module Types Feature + Interface Service + Interface

52. Feature A screen or a flow in the app

53. Service Manage shared state or resources

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56. How do we enforce these best practices?

57. /services /service_interfaces /features /feature_interfaces

58. def service_interface( name, deps): max_visibility = [ "//ios/feature_interfaces/...", "//ios/features/...", "//ios/service_interfaces/...",

    "//ios/services/...", ]

59. service_interface( name = "Networking", deps = [ "//ios/service_interfaces/Logging", ], )

60. feature( name = "Booking", deps = [ "//ios/service_interfaces/Networking", "//ios/service_interfaces/WishListService", ],

    )

61. iOS Platform

62. Module creation needs to be easy

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65. rake make:module

66. > Provide the type of module you want to create:

    1: Non Platform 2: Feature 3: Feature Interface 4: Service 5: Service Interface 4 > New module name: Swiftable > Provide a high level description of this module: This is a module to present at Swiftable

67. Buck Human readable dependencies https://github.com/airbnb/BuckSample

68. feature( name = "Booking", deps = [ "//ios/service_interfaces/Networking", "//ios/service_interfaces/WishListService", "//ios/feature_interfaces/HelpCenter",

    ], )
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70. Feature A screen or a flow in the app

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74. Dev Apps

75. ~1 min Dev Apps

76. Big buckets Small playgrounds

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78. How do we get there?

79. ~100 modules One module type: /libraries

80. libraries/AirbnbBooking libraries/AirbnbBusinessTravel libraries/AirbnbHelpCenter libraries/AirbnbListings libraries/AirbnbNetworking libraries/AirbnbWishLists ...

81. Before iOS Platform /libraries

82. On the iOS Platform /services /service_interfaces /features /feature_interfaces

83. How to get everybody on the iOS Platform?

84. Remove libraries/ and start over

85. !

86. Progressively migrate

87. Let's migrate WishLists Data Source

88. libraries/WishLists

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92. What are the dependency rules for libraries/?

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94. Inbound dependencies Outbound dependencies

95. Inbound dependencies Outbound dependencies

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97. The interface module has stricter rules

98. Migrate all the call sites

99. As the owner of WishLists We don't control these

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101. Calculated tech debt

102. Inbound dependencies Outbound dependencies

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104. we know our usage of Networking

105. We control our dependencies

106. Allow inbound dependencies from libraries/ Don't allow outbound dependencies to

     libraries/

107. libraries/ has access to the iOS Platform

108. The iOS Platform doesn't have access to libraries/

109. Code on the iOS Platform has good boundaries

110. while we allow for easier migration

111. def service_interface( name, visibility = []): max_visibility = [ "//ios/feature_interfaces/...",

     "//ios/features/...", "//ios/service_interfaces/...", "//ios/services/...", ] add_visibility_for_legacy_module_structure(max_visibility)

112. def add_visibility_for_legacy_module_structure(visibility): visibility.extend([ "//ios/libraries/...", ])

113. We started migrating from the bottom up

114. Try it ourselves !rst

115. Pilot with others teams

116. Should I implement this?

117. Most likely NO

118. There's no silver bullet

119. Adapt

120. Summary 1. Figure out where you're struggling 2.Create and document

     best practices 3.Automate best practices where needed

121. ¡Gracias! franciscodiaz.cl/talks