Continuous deployment is a a process that allows companies to release software in minutes instead of days, weeks, or months. Pascal-Louis Perez will describe how to use continuous deployment to iterate so fast that you run circles around the competition. He will cover the high level concepts as well as the nitty gritty details including examples from the continuous deployment system that he and his team developed at KaChing. Pascal-Louis is the VP of Engineering and CTO at KaChing, where he practices continuous deployment continuously. He previously worked at Google and holds a Master's degree in Computer Science from Stanford University.

1. Continuous Deployment at kaChing #leanstartup

2. “Connect investors with outstandinginvestment managers” Pascal-Louis Perez, kaChing Group Inc.

3. Pascal-Louis Perez, kaChing Group Inc. Assets Managed by Mutual Funds in the US $11,000,000,000,000

4. Pivot Our vision of bringing the quality of Ivy League Endowment management to retail is unaltered Powering a marketplace where customers entrust high end managers with their money in separately managed accounts. We are SEC & FINRA regulated. Three years ago, kaChing was a fantasy stock trading app for young adults on facebook. Our strategy was to create an eco system where avid amateurs could rise through the ranks and make it to pro league. Pascal-Louis Perez, kaChing Group Inc.

5. Constant tension between product and development. Right architecture only in the context of how it is used. Initially, you don’t know for sure how something will be used! We’ve adopted proportional investing Build cheap When you spend X hours of time fixing problems Spend a corresponding X hours improving the feature Pascal-Louis Perez, kaChing Group Inc. Build “Right” Features

6. Strive for 80% of the value for 20% of the cost Realize that 80% of what you build will go to waste. Validate before investing more time! Pascal-Louis Perez, kaChing Group Inc. 80/20

7. Errors Are Costly! Continuous Deployment is a mission critical way of running our business which provides tremendous value Errors are costly Brand impact SLA penalties And when you’re regulated, there’s also liabilities Turning the wheels on the software with high confidence provides tremendous business value Pascal-Louis Perez, kaChing Group Inc.

8. Deploy Fast and Often Pascal-Louis Perez, kaChing Group Inc.

9. What is Continuous Deployment? Continuous, successful and repeatable methodology to deploying code Automates every steps of taking checked in code and making it run on production servers, used by customers Pascal-Louis Perez, kaChing Group Inc.

10. e.g. Twenty Deployments a Day Pascal-Louis Perez, kaChing Group Inc.

11. Release is a Marketing ConcernReducing Code Inventory is Engineering’s Job Pascal-Louis Perez, kaChing Group Inc.

12. Homage to Gursky: 'Kirksky‘copyright 2010 by Kirk Crippens Supermarket Analogy (Think Safeway) You don’t close the store to fill the shelves! Continuously get fresh merchandise out For product releases, simply close or hide the aisle

13. Traditional Release Organization Software organized as a tree Trunk is what goes on production, it is The Truth Engineers work on features in branches Features get integrated into trunk Release train on regular cyclic period QA ensures correctness of each train P1 bugs get patched back into the train Flip the switch release Pascal-Louis Perez, kaChing Group Inc.

14. Timeline Pascal-Louis Perez, kaChing Group Inc. QA Stage Release Fix P1 Bugs Development Cut a Release Integrate Patches 1-4 Weeks

15. Timeline, Revisited Pascal-Louis Perez, kaChing Group Inc. Deployment Automated QA Stage Fix P1 Bugs Release Development or Testing Cut a Release Integrate Patches Monitoring Experiments 5-10 Minutes

16. Experiments Split features which are not finished“if press person, show the new home page”if (isInExperiment(NEW_HOME_PAGE)) { …} else { …} Pascal-Louis Perez, kaChing Group Inc. (Yes, this is just like A/B Testing)

17. True Story Investment managers calls, comments about unintuitive trading flow. Improvements are made, and deployed within the next 20 minutes. We call him back “What do you think of the improvement?” Pascal-Louis Perez, kaChing Group Inc.

18. Benefits of Continuous Deployment It allows quick iterations Obsoletes processes, e.g. “cutting a release” Reduces risk Everyone is aware of production No one throws code over the wall Exposes 24x7 operational requirements Trunk stable Pascal-Louis Perez, kaChing Group Inc.

19. Continuous Deployment ImmuneSystem Culture ContinuousIntegration Pascal-Louis Perez, kaChing Group Inc. Test DrivenDevelopment

20. kaChing’s Architecture Service oriented system Vertical sharding Everything uses the same platform kawala Coordination using ZooKeeper Data interchange using JSON and Protobufs Pascal-Louis Perez, kaChing Group Inc.

21. Typical Stack Clustered services, multiple instances Replicated databases (e.g. MySQL, Redis, …) Caching (e.g. memcached) Denormalized data (e.g. Voldemort) Pascal-Louis Perez, kaChing Group Inc.

22. Timeline, Revisited Pascal-Louis Perez, kaChing Group Inc. Development Deployment Testing Monitoring

23. Development Trunk stable Small, frequent commits Unreleased features live behind experiments Forward & Backward compatibility Responsive code review Pair difficult problems Trivial rollbacks

24. Testing Philosophy Only automated testing matters If it isn’t tested, it isn’t finished or correct Write testable code Embrace abstractions Testing is cross functional, we all own quality

25. Benefits of TDD It allows quick iterations It empowers engineers to change anything, and as such helps in scaling the team It is more cost effective than debugging It obsoletes the need for functional QA It facilitates continuous refactoring, allowing the code to get better with age It attracts the right kind of engineers Pascal-Louis Perez, kaChing Group Inc.

26. Types of Testing Unit Testing - does the code work? Integration Testing - does the code work together? Regression Testing - learn from your mistakes Frontend Testing - a whole different ballgame

27. Defensive Testing Capture invariants in tests Nightmare scenarios A common conversation at lunch: Alice: What would happen if X blew up? Bob: uh... the site would go down. Fix it, test for it

28. Implementation Frameworks: junit, dbunit CI: Hudson Frontend: Selenium

29. Life of a Deployment Pascal-Louis Perez, kaChing Group Inc. DM PM PM PM ZK

30. Life of a Deployment Pascal-Louis Perez, kaChing Group Inc. DM PM PM PM ZK

31. Life of a Deployment Pascal-Louis Perez, kaChing Group Inc. DM PM PM ZK

32. Life of a Deployment Pascal-Louis Perez, kaChing Group Inc. DM PM PM PM ZK

33. Life of a Deployment Pascal-Louis Perez, kaChing Group Inc. DM PM PM PM ZK

34. Deployment Exponentially increasing group sizes Increased monitoring during deployment Self Test Automated rollbacks

35. Stability Cluster everything As little global state as possible Maintain global state through ZooKeeper Monitor everything

36. ZooKeeper Reliable Distributed Synchronization Service Discovery Service Status Coarse locking

37. Implementation Building: ant Deploying: rpm, yum Monitoring: nagios, jcollectd, RRDtool, jmx Custom automation

39. Monitoring Philosophy Prefer business metrics Monitor statistical deviations not absolute values Automatically annotate graphs

40. Monitoring Errors False negatives - errors of omission False positives - errors of implementation

41. End to End Monitoring Run Selenium on production Accessibility, Speed Ad-hoc Keynote - customized for our flows Must control data creation, analytics impact

42. #future-developments Pascal-Louis Perez, kaChing Group Inc.

43. Quarantining Isolate new releases Flexible partitioning of requests Gradually shift load to fresh services Pascal-Louis Perez, kaChing Group Inc.

44. Describing Infrastructure Many moving parts nagios, collectd, backups, services, databases, … Consistency is key Adding new tools should be easy and thorough Standardize best practices Pascal-Louis Perez, kaChing Group Inc.

45. TGIF? Pascal-Louis Perez, kaChing Group Inc. We will be hosting a TGIF in August in our office@pascallouis / @kachingeng

46. References We’re Recruiting jobs@kaching.com kaChing’s blog http://eng.kaching.com kawalahttp://bit.ly/kawala Deployment Infrastructure http://eng.kaching.com/2010/05/deployment-infrastructure-for.html Extreme Testing http://bit.ly/9bOFaA Writing Testable Codehttp://googletesting.blogspot.com/2008/08/by-miko-hevery-so-you-decided-to.html The Testability Explorer Bloghttp://misko.hevery.com ZooKeeperhttp://bit.ly/kc-zookeeper Lessons Learned http://startuplessonslearned.com Pascal-Louis Perez, kaChing Group Inc.