Whoops! Where did my architecture go?

Slides of the talk on maintaining software architecture in Java applications I gave at GeeCON Prague 2014. @springcentral

1. Whoops!
   Where did my architecture go? Architecture management for Java applications ! Oliver Gierke
6. Background 5 years of consulting Lots of code reviews Eoin Woods‘ talk on InfoQ Lot of input from fellows
7. "If you think architecture is expensive, try no architecture.
   
8. "Architecture is like weather: you can’t have none.
   
9. Macro VS. Micro Architecture
10. Orders Inventory Billing Macro-Architecture Micro-Architecture JMS REST AMQP
11. JRuby Java Scala Macro-Architecture Micro-Architecture AMQP JMS REST
12. Neo4j RDBMS MongoDB Macro-Architecture Micro-Architecture JMS REST AMQP
13. Neo4j RDBMS MongoDB Macro-Architecture Micro-Architecture from Stefan Tilkov -
 Breaking the Monolith JMS REST AMQP
14. Roadmap Divide and conquer Of layers and slices A plain Java based approach
15. Architecture 101
16. Know your dependencies
17. Explicit / Visible
    dependencies
18. Granularity Modules Layers Vertical slices Subsystems
19. Granularity Java ARchive Package Class
20. Divide and conquer
21. Component Single unit to understand
22. Component Single unit to change
23. Component Scope of risk of change
24. B Smaller unit to understand A
25. B Reduced risk of change A
26. B Cost of separation A
27. B Definition and maintenance
    of dependencies A
28. "Meanwhile, in my friend’s project…
29. How do I add a feature?
30. How do I add a feature? New
 Feature © Eberhard Wolff
31. Of layers
    and slices…
32. Presentation Service Data Access Account Customer Core
33. Layers Well understood Known to developers Less important to business
34. Slices Hardly understood New to developers Key for business requirements
35. Presentation Service Data Access Account Customer Core
36. "How to implement an architecture
    inside a codebase?
37. Architecture
    VS.
    Codebase
38. "How to implement an architecture
    inside a codebase?
39. "How to maintain
    an architecture
    inside a codebase?
40. Code analysis JDepend Sonarcube
41. Sonargraph Formerly known as SonarJ
42. Demo
43. A plain Java
    based approach
44. "How far can we get with plain Java means only?
45. Presentation Service Data Access Account Customer Core
46. Packages
47. ….layer.slice
    ….slice.layer
    ….slice
48. ….web.core
    ….service.core
    ….repository.core
49. ….core.web
    ….core.service
    ….core.repository
50. ….core
    ….customer
    ….account
51. "Why the f#$k
    should I even care?
52. "Does it make
    a difference?
53. Dependency management
54. "You only need to manage, what you can refer to…
55. Layers first Leaks slice internals Lower layers visible to everyone
56. Slices first/only Start with package per slice Expose interfaces and domain types Keep implementations private
57. Slices first/only Encapsulates business module Internals understood anyway
58. "Start with less packages and the least visibility possible…
59. Presentation Service Data Access Account Customer Core
60. Presentation Service Data Access Account Customer Core
61. Demo
62. Take-aways Know your dependencies On every granularity Start as strict as possible Get lenient where necessary
63. Resources Spring Data JPA @ GitHub Sonargraph jQAssistant Blogpost
64. Sample Code http://github.com/olivergierke/
 whoops-architecture
65. Oliver Gierke Spring Data Project Lead ! ogierke@pivotal.io olivergierke www.olivergierke.de
66. Thanks & Credits Eoin Woods - Talk @ InfoQ Stefan Tilkov - Talk @ InfoQ Eberhard Wolff - Slides @ Slideshare