The document provides an overview of development at Twitter including that it has over 1800 engineers across multiple offices working on various aspects of the platform from mobile to frontend. It discusses some of the technical challenges of building Twitter at scale including handling over 500 million tweets per day. It also outlines many of the tools, practices, and culture at Twitter such as their use of Git, JIRA, Hipchat, open source contributions, hack weeks, and emphasis on learning. Finally, it provides some career advice tips around contributing to open source, networking, branding yourself, and negotiating job offers.

1. #TwitterDev
Life at Twitter and some career advice
Chris Aniszczyk (@cra)

2. Development at Twitter
intro tools practices open source

3. Howdy, I’m @cra!

4. https://twitter.com/TwitterEng
• ~1800 Engineers
• 50% of the company is engineers
• From Datacenter to Kernel to JVM to Mobile to Frontend (etc)
• Engineering Offices
• SF, Seattle, Boulder, NYC, London, Tokyo
Twitter Engineering

5. LOL 1800 Engineers for Tweets?
(Inspired by @shit_hn_says: I can just build Twitter clone over the weekend)

6. Twitter is global, open
and real-time

7. Twitter, Inc. | Confidential

8. Why is Twitter actually hard?

9. HackPrinceton - November 14-16, 2014@TwitterAds | Confidential
300M+
500M+
80%
Active users
Tweets / Day
of users are
mobile users
2006 2015

10. 500,000,000 Tweets/Day
3,500,000,000 Tweets/Week

11. ~6000 Tweets/Second
(steady state)

12. Miyazaki 2011
25,088 TPS (NYE 2013: 33,338 TPS)
バルス! (“Death to Twitter”)

13. Miyazaki 2013
25,088 TPS 143,199 TPS
https://blog.twitter.com/2013/new-tweets-per-second-record-and-how
バルス! (“Death to Twitter”)

14. Twitter is simple on the surface
Complexity lies beneath…

15. Profiles / Gizmoduck
Who to Follow / S&R
Trends / S&R
Home timeline / TLS
PTw / Ads
Expanded media / Cards
Contact import / Growth
Compose / Tweetypie
Translation / i18n
DMs / Social
Discover / S&R

16. Development at Twitter
intro tools practices open source

17. VERSION CONTROL
Git (GitHub for Open Source)
Monorepo for back-end services

18. ISSUES / TICKETING
Atlassian JIRA

19. CHAT
Hipchat

20. CHAT BOTS
Hubot

21. DOCUMENTATION
Confluence / Docbird

22. CODE REVIEWS
Gerrit
ReviewBoard

23. VIDEO CONFERENCING
Bluejeans / Google Hangouts

24. Language Frameworks
• scalaTest, junit (JVM)
• jasmine, qunit (JavaScript)
• webdriver, unity (Integration)
• UIAutomation / Robotium (mobile)
• rspec, test/unit (Ruby)
TESTING TOOLS

25. Development at Twitter
intro tools practices open source

26. TWITTER UNIVERSITY
A culture of learning!

27. CONTINUOUS INTEGRATION
Jenkins and Mesos Clusters

28. DOG FOOD
go/iosnightly
go/androidbeta
go/preflight

29. PREFLIGHT TESTING
Every employee tests first
(slow rollout to users 1% etc)

30. #HACKWEEK (Fix-It Weeks)
Every quarter

31. DEMO HOUR (#Treephy)
Every 2 weeks, demo progress

32. OBSERVE ALL THE THINGS
http://github.com/twitter/zipkin

33. • timed launching, feature flags, access, kill switch
DECIDER (FEATURING FLAGS)
if (request.isDeciderAvailable(“my_feature_name”)) {
// do this
} else {
// do that
}
go/decider

34. • experiments, A/B tests
DDG (EXPERIMENTATION)
import com.twitter.web.util.abdecider.experiments.MyExperiment
MyExperiment.getExperimentBucketName(request) match {
case Some(“control”) => ...
case Some(“expand_images”) => ...
case Some(“expand_videos”) => ...
}
go/ddg

35. RUNBOOKS
Guides on running services

36. SELF SERVICE SERVICES
Apache Mesos / Aurora

37. Development at Twitter
intro tools practices open source

38. Twitter Runs on Open Source

39. SCM / ISSUES / WIKI
GitHub (Git)
https://github.com/twitter

40. CONTINOUS INTEGRATION
Travis CI
https://travis-ci.org/twitter

41. CODE COVERAGE
Coveralls (aggregation)
https://coveralls.io/r/twitter

42. STATIC ANALYSIS
Code Climate*
https://codeclimate.com

43. CAREER ADVICE: 7 TIPS

44. Find newbie-friendly* open source projects…
Contribute to them!
*https://www.google-melange.com/gsoc/homepage/google/gsoc2015

45. Find a mentor early at work and outside of it
(You will learn, save time and opportunities will find you)
https://fedoraproject.org/wiki/Mentors

46. Don’t specialize early in your career
Technology changes like crazy, stay curious and learn new things
(Twitter was a RoR shop and moved to the JVM)

47. Not networking? you’re NOT WORKING!
Go to meetups: http://capitalfactory.com/learn/events/
Speak at events/conferences: https://lanyrd.com
(I know this may be hard for some CS students)

48. Control your public image*, you are a brand
(Brand yourself for the career you want, not the job you have now)
Get on Github: https://github.com
Get on LinkedIn: https://linkedin.com
Get on Twitter: https://twitter.com
Get on IRC (or Slack): irc://irc.freenode.net
Get on Stackoverflow: https://stackoverflow.com
*http://www.businessinsider.com/twitter-fired-2011-5

49. Interview every year, practice makes perfect
This will also help sharpen skills and establish your worth
(Read Cracking the Coding Interview: http://www.careercup.com/book)

50. Learn negotiation skills, get multiple offers
Don’t sell yourself short, times are good these days
See Glassdoor for salaries: https://glassdoor.com

51. Q&A
#ThankYou
zx@twitter.com (@cra)
We’re always hiring (jobs.twitter.com)
t.co/UTAustin and t.co/AustinIntern