Video and slides synchronized, mp3 and slide download available at URL http://bit.ly/Kfuwmc. Rachel Laycock advises on designing systems for rapid deployment, avoiding delivering pitfalls by using micro services and evolutionary architecture. Filmed at qconsf.com. Rachel Laycock works for ThoughtWorks as a Lead Consultant with 10 years of experience in systems development. She has worked on a wide range of technologies and the integration of many disparate systems. Since working at ThoughtWorks, Rachel has coached teams on Agile and Continuous Delivery technical practices and has played the role of coach, trainer, technical lead, architect, and developer.

1. Adopting Continuous
Delivery
Adjusting your Architecture
RACHEL LAYCOCK
http://thoughtworks.com
@rachellaycock

2. Watch the video with slide
synchronization on InfoQ.com!
http://www.infoq.com/presentations
/adopting-continuous-delivery
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4. Continuous Delivery
Our highest priority is to satisfy
the customer through early and
continuous delivery of
valuable software.

5. You can’t have
Continuous Delivery

6. Once upon a time I was
a happy developer...

7. I thought I knew what
Continuous Delivery was

8. I was even doing it on my
projects

9. Then one day...

10. ...a client wanted
Continuous Delivery

11. ...and we said “sure”

12. ...but 3 months later they
were still asking...

13. “Where is my
Continuous Delivery?”

14. So what went wrong?

15. Their code base was
huge and complex

16. I learned something from
that...

17. ...something I will share with
you

18. 1. Conway’s Law is THE LAW
2. Keep things small
3. Evolve your architecture

19. agile 101
"Agile" team
Analysis + Design
Centralized QA
IT Operations
Development
Integration + QA
Release and operation
Testing + Showcase
Customer
Iteration
0
1
2
3
4
The "last mile"

20. continuous delivery
Customer
Delivery team
Constant flow of new features into production
software always production-ready
releases tied to business needs, not
operational constraints

21. releasing frequently
feedback from users
reduce risk of release
John Allspaw: “Ops Metametrics” http://slidesha.re/dsSZIr

22. releasing frequently
feedback from users
reduce risk of release
real project progress

23. CD is BIG!
Organisational Alignment
Release Management
Architecture
Quality
Assurance
Continuous
Integration
Configuration
Management
Data
Management
Environments
& Deployment

24. Stuff that's hard to
change

25. ?

26. 1. Conway’s Law is THE LAW

27. Conway's Law: "organisations which design
systems ... are constrained to designs which
are copies of the communication structures of
these organisations"

28. Fred Brooks (mythical man-month): “Because the design
that occurs first is almost never the best possible, the
prevailing system concept may need to change.
Therefore, flexibility of organisation is important to
effective design.”

29. The wrong side of the law

30. Some time passed...

31. Ball of Mud

32. Dependency Hell

33. dependencies
Reports engine
Framework
Settlement
engine
CDS pricing
library
Pricing engine
Portfolio
management
application

34. Brownfield

35. untangling

36. strangler pattern
http://paulhammant.com/2013/07/14/legacy-application-strangulation-case-studies/

37. feature toggles
http://martinfowler.com/bliki/FeatureToggle.html

38. branch by abstraction
http://continuousdelivery.com/wp-content/uploads/2011/05/branch_by_abstraction.png

39. The law on your side

40. ***.com.au
***.com.us
Web
Services
Data
***.com.it

41. 2. Keep things small

42. What is a
Micro Service?
http://www.infoq.com/presentations/Micro-Services

43. The monolith
backlash

44. Simple and lightweight

45. Why we want them?

46. Things to consider...

47. Communication

48. Monitoring

49. Testing

50. Scripting

51. Replaceable
Services

52. 3. Evolve your architecture

53. Evolutionary Architecture
& Emergent Design

54. Greenfield

55. Principles of
Evolutionary Architecture
1. Last Responsible Moment
2. Architect for Evolvability
3. Postel’s Law
4. Architect for Testability
5. Conway’s Law

56. 1. Last Responsible Moment

57. 2. Architect for Evolvability

58. 3. Postel’s Law

59. 4. Architect for Testability

60. 5. Conway’s Law

61. 1. Conway’s Law is THE LAW
2. Keep things small
3. Evolve your architecture

63. Architect for Build,
Run and Deploy

64. Thank you!
RACHEL LAYCOCK
http://thoughtworks.com
@rachellaycock

65. ?

66. Resources
Books:
• Continuous Delivery - Jez Humble, Dave Farley
• Working Effectively with Legacy Code - Michael Feathers
• Release It - Michael Nygard
• Domain Driven Design - Eric Evans
Articles/Blogs:
• Branch by Abstraction - Jez Humble:
http://continuousdelivery.com/2011/05/make-large-scale-changes-incrementally-with-branch-by-abstraction/
• Branch by Abstraction - Paul Hammant:
http://paulhammant.com/blog/branch_by_abstraction.html/
• Feature Toggles - Martin Fowler: http://martinfowler.com/bliki/FeatureToggle.html
• Evolutionary Architecture - Neal Ford: http://www.ibm.com/developerworks/views/java/libraryview.jsp?
search_by=evolutionary+architecture+emergent+design:
• Ball of Mud: http://www.laputan.org/mud/
• Deming - http://leanandkanban.wordpress.com/2011/07/15/demings-14-points/
• Coding Horror: http://www.codinghorror.com/blog/2007/11/the-big-ball-of-mud-and-other-architecturaldisasters.html
• Who needs an architect: http://martinfowler.com/ieeeSoftware/whoNeedsArchitect.pdf
• Evolutionary Architecture and Emergent Design: http://www.ibm.com/developerworks/java/library/j-eaed1/
index.html
• Strangler Application: http://martinfowler.com/bliki/StranglerApplication.html
• Micro services: http://www.infoq.com/presentations/Micro-Services

67. Watch the video with slide synchronization on
InfoQ.com!
http://www.infoq.com/presentations/adoptingcontinuous-delivery