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