This document summarizes an agenda for a Pinterest Engineering meeting. It includes discussions on mobile growth and monetization, deploying and shipping code. Specific topics that will be covered include scaling user education on mobile, growth strategies like user education, monetization through data, and how Pinterest deploys and ships code. Speakers will discuss mobile features, how user growth is driven through education, monetizing user data, and ensuring smooth code deployment.

1. Discover Pinterest Engineering

2. Agenda
!
Mobile & Growth:
Monetization & Data:
Deploying & Shipping Code:
Wendy & Dannie
Pawel
Chris & Jeremy

3. Wendy Lu
Mobile
Scaling User Education on Mobile
The Experience Framework
Dannie Chu
Growth

4. User Education

5. Motivation?

6. User Education leads to Engagement

7. First Pin Education

9. Challenges

10. 1. Preserve a great user experience

11. Conflicting Education

12. Never-ending Stream of Nags

13. Nag that never goes away

14. 2. Targeting

15. Are you a new user? Invite some friends!

16. Do you have an empty homefeed? Make it better!

17. 3. Rapid Experimentation

18. Experiment with messaging w/o requiring a release

19. 4. Keep the client code clean

20. Solution?

21. The Experience Framework

22. Conflicting Experiences

23. Experiences and Placements
Nag Placement Home view Placement
Pin Tutorial Card
Placement

24. AB Experimentation, Simple Client Code

25. Experiences are delivered to the client at runtime

26. Experience Framework
Decision Engine
Configuration
Handlers
Admin
DashboardAPI
Servers
AB Experiments
Framework Kafka
(logging)
HBase
(User States,
Experience States)
API Servers
API ServersCascading/
MapRed
User State
Batch Loader
Clients
SDK
SDK
What
experience
should the
user see?
Experience Framework

27. Deep Dive: Nags

28. What are nags?
•Important information which we
occasionally display at the top of
a user’s feed
•Can be a Call to Action “Confirm
your email” or an announcement
“You can now add a map to any
board!”

29. Enter: The Experience Framework

30. Enter: The Experience Framework
•Each time we reload the home
feed, ask the experience
framework: What should I show
in this nag?

31. Single Nag Manager that relies on the experience
framework to give it the contents to render
Nag Manager
•Experiment with nag messaging, call to actions, images
•Add any new nag dynamically, controlled from the backend.
•Cool-down management - should not see more than one nag in a set
period of time

32. What does that nag data look like?
Handling actions
"bg_img_url_2x" = "http://mobile-
assets.pinterest.com/iphone/nags/invite-
mail@2x.png"
"title_text" = "Pinspire your friends!"
"detailed_text" = "Know someone who'd like
Pinterest? Invite them along."
"button1_text" = "No, Thanks”!
"button1_uri" = ""!
"button2_text" = "Invite Friends"!
"button2_uri" = "pinterest://invite_friends"

33. Handling Actions
•All initialization and presentation of view controllers is handled through a
central “Navigation Manager.”
• Centralizes code to create and present view controllers
• Consistency to other platforms for deep links
•Allows dynamic insertion of nags from the backend without having to write
new client code and submit a new release

34. [[NavigationManager sharedManager]
handleURL:[NSURL
URLWithString:@“pinterest://
invite_friends]];
Navigation Manager
self.presentationDelegate
presentInviteFriends

35. Deep Dive: New User Experience

36. New User Experience
What is NUX?
!
•The set of initial tutorials and education presented to a user after they
register

37. Personalize a user’s content immediately after signup
Connect with Friends Choose Interests

38. Next, teach users how to Pin

39. Experiment between classic user ed and NUX

40. Experiment between classic user ed and NUX
•When doing experiments where we need to call the network to get the
user’s treatment group, need to make sure we’re not adding perceived
latency
• Structure view controllers in a way that you can asynchronously load in the modules
dependent on the treatment group
• If need to transition to different view controllers, set a time out in which we transition
to the control treatment
• “Be Fast or Fail Fast”

41. 1 step vs. 2 steps vs. 3 steps
Experiment with different versions of NUX

42. Experiment with different versions of NUX
•Backend controls all strings, allowing us to dynamically experiment with
different text (Messaging, titles, calls-to-action)

43. steps = (
{
"continue_button_text" = Continue;
"detailed_text" = "Tap a network to find people who share your interests.";
"follow_button_text" = "Follow selected people";
step = 1;
"title_text" = "First things first";
"total_steps" = 2;
},
{
"completion_message" = "Finding Pins for you...";
"continue_button_text" = "Tap at least {0} more to continue";
"detailed_text" = "Tap whatever you're interested in these days.";
"finish_text" = Finish;
"num_interests" = 5;
"skip_text" = "Pinterest is much more interesting when you tell us what you like.";
step = 2;
"title_text" = "Pick 5 interests";
"total_steps" = 2;
}
);
After signup, request all data for NUX
Enter: Experience Framework

44. Supports dynamic number and order of steps
NUXViewController : UINavigationController
•Maps an array of display data to an array of view controllers
•Protocol method advanceToNextStep called by each child view controller
• Checks the array it keeps for the next view controller to push
JSON dict for Intro
JSON dict for Friend Selector
JSON dict for Interests Selector
NUXIntroViewController
NUXConnectViewController
NUXInterestsViewController

45. Wins from Experience Framework
•Single place in the backend that manages all experiences for all platforms
•Dynamically trigger display of content
•Conflict resolution for educations that touch the same views
•Experiment with flows, messaging, and images

46. engineering.pinterest.com

47. Pawel Garbacki
Software Engineer, Monetization
Pinterest Secor
Zero-data-loss log persistence service

48. Pinterest is a data driven company
•Data matters
• 100+ experiments active at a given point in time
• 1500+ tracked metrics
• 200+ log types

49. We produce a lot of data
•We produce a lot of data
• PBs of data in S3, growing by Tens of TB a day
• Hundreds of production hadoop jobs, processing about half a PB of data each day

50. Singer
(logging
agent)
App
Data pipeline
Local
Disk
S3Kafka
(log collector)
Secor
(log saver)
Storm
(realtime
stats)
Hive (hadoop
analytics)
Redshift (ad
hoc queries)

51. Singer
(logging
agent)
App
Local
Disk
S3
Kafka (log
collector)
Secor (log
saver)
Storm
(realtime
stats)
Hive (hadoop
analytics)
Redshift (ad
hoc queries)
Data pipeline
20B messages/day

52. Kafka 101
•Distributed pub-sub service
•Designed for high throughput
Producer Producer Producer
Consumer Consumer Consumer
Kafka
cluster

53. Anatomy of a topic
•Topic is a category to which messages are published
•Partition is a ‘shard’ of a topic controlling the level of consumption parallelism
•Messages are assigned unique identifiers called offsets
1 2 3 4 5 6 7 8 9 10 11 12
1 2 3 4 5 6 7 8 9
1 2 3 4 5 6 7 8 9 10 11 12
Writes
Partition 0
Partition 1
Partition 2

54. Save the day
•Kafka is optimized for local writes
•Local disk capacity is good for a few
days worth of data
•Data needs to be saved (at least) daily
to long term storage - Amazon S3

55. How soon is “eventually”
•Amazon S3 is a cloud file system
•Eventual consistency model
• No guarantees on when uploaded data will become visible to the readers
• No monotonicity - data available in the past may magically disappear

56. Secor design guidelines
•Objectives:
• Persist Kafka logs to S3
• Cause no data loss
• Work properly with eventual consistency model
•Properties:
• Horizontal scalability
• Fault tolerance
• Customizability

57. No-S3-reads principle
•Secor never reads data from S3
• Lightweight metadata is stored in strongly
consistent state repository
•Strategic choice of file names
• s3n://logs/<topic>/
<generation>_<partition>_<start_offset>
• <generation> represents software compatibility
version
• Inconsistencies introduced by consumer failures
get fixed automatically by file overwrites

58. Date clustering
•Data processing tools rely on date-
partitioned directory structure
• s3n://logs/event/dt=2014-04-04/
•Timestamps extracted from messages on
the fly
•Support for pluggable parsers for thrift,
json, etc.

59. https://github.com/pinterest/secor

60. Chris Danford (@chrisdanford)
Jeremy Stanley (@rouxbot)
Web Team
From Development to Production
The life of web features

61. Develop Review Deploy Measure

62. Develop Review Deploy Measure

63. Developing - Ideal state
•able to iterate quickly
•easy errors caught automatically
•easy-to-understand and powerful abstractions

64. Fast iteration
Developing
•Build tasks and dependencies modeled as a graph
•“cumberbatch” watches for changes of file contents
•“orchestrator” knows tasks and dependencies
•build the minimum tasks to heal damage in the graph
•maximize parallelization of tasks
•built on Grunt - access to large library of build tasks

65. Self-healing build graph
sprite/*.png
sprite task
sprite.png sprite.scss
Sass task
component/*.scss
components.css
imagemin task Autoprefixer task CSSlint task

66. Self-healing build graph
sprite/*.png
sprite task
sprite.png sprite.scss
Sass task
component/*.scss
components.css
imagemin task Autoprefixer task CSSlint task

67. Self-healing build graph
sprite/*.png
sprite task
sprite.png sprite.scss
Sass task
component/*.scss
components.css
imagemin task Autoprefixer task CSSlint task

68. Self-healing build graph, example 2
sprite/*.png
sprite task
sprite.png sprite.scss
Sass task
component/*.scss
components.css
imagemin task Autoprefixer task CSSlint task

69. Self-healing build graph, example 2
sprite/*.png
sprite task
sprite.png sprite.scss
Sass task
component/*.scss
components.css
imagemin task Autoprefixer task CSSlint task

70. Linting
Developing
•catches easy bugs
•enforces consistent style
•pyflakes
•pep8
•jshint
•CSSLint
•custom RegEx linting

71. RegEx-based linter
$(‘.item’).addClass(‘selected’);
BoardPicker.js
this.$(‘.item’).addClass(‘selected’);

72. Static analysis / type safety
Developing
•Google Closure Compiler
•template static analysis
• validation of template inheritance
• extract used option variable names
•Thrift clients for service calls (Python) and shared constants (JavaScript)

73. Closure Compiler - type safety

74. Generated constants from Thrift

75. Abstractions
Developing
•component framework
• styles are scoped to the component
• DOM access is scoped to the component’s DOM
• “events up, methods down”
• scaffolding script
•live component catalog - discovery of existing components
•autoprefixer, spriting - remove boilerplate

76. component catalog

77. spriting
.thumbsUpButton {!
@include inline-image(‘sprites/main/thumbUp');!
}
Usage

78. Develop Review Deploy Measure

79. Reviewing - Ideal state
•the most-relevant person is reviewing changes
•integration-type issues are caught

80. Code Reviews
Reviewing
•local test runner script runs Jasmine and Node tests parallelized
•“PR watcher” tool - visibility of relevant PRs
•code review process - R+, E+

81. Parallelized Jasmine tests in PhantomJS

82. Github Watcher tool

83. Integration problems are caught
Reviewing
•PRs trigger a build and tests - 3 minutes
•latest.pinterest.com is continuously deployed from “head”
•Selenium integration tests run against every deploy

84. Pull request builds

85. Selenium

86. Develop Review Deploy Measure

87. Deploying - Ideal state
•code deploys are invisible to users
•frequent and non-disruptive to developers
•immediate rollback when there’s a problem

88. User experience
Deploying
•stickiness to a version
•flip nearly instantaneously between builds
• reduce version thrashing
• worry less about (style mismatches, JS errors due to data format mismatch with
server)
•asset versioning

89. Serving multiple application versions
new!
sessions
old!
sticky!
sessions
A B
all!
sessions
B
1 2

90. Serving multiple application versions, cont’d
3 4
new!
canary!
sessions
all!
non-canary!
sessions
B C
new!
sessions
old!
sticky!
sessions
B C

91. Asset versioning
logo.png
rename
hash file!
contents
logo.59aa9183.png
bundle.css
background-image: logo.png
background-image: logo.59aa9183.png
update references
bundle.css
bundle.907389d8.css
rename
hash file!
contents

92. When things go wrong
Deploying
•experiments dashboard - turn off experiments instantaneously
•version rollback is nearly instantaneous

93. Develop Review Deploy Measure

94. Monitoring health
A/B Dashboard
•A/B dashboard key metrics
•Sentry
•Stats dashboard
•Alarms - Monit, PagerDuty

95. A/B Dashboard

96. Sentry

97. Sentry error emails

98. Results

99. Results
•5 engineers on web team
•all teams at Pinterest developing their own web features on our platform
•components re-used across teams
•2 scheduled deploys a day
•anomalies in key metrics surfaced immediately
•100s of simultaneous experiments