The document discusses challenges in building APIs for mobile and distributed systems, including increasing mobility and agility while maintaining stability. It recommends REST and hypermedia as architectural models, noting that hypermedia enables remote and evolvable systems. The document also examines SOAP, CRUD, and hypermedia approaches, and advocates for a focus on usability, scalability, and evolvability in API design using the "USE" paradigm.

1. SOA and APIs:
Fearless Lessons from the Field
Mike Amundsen
Principal API Architect
@mamund
1

2. Fearless
2

3. Fearless
3

4. Fearless
4

5. Mike Amundsen
 Architect, Developer, Presenter
 Hypermedia Junkie
 Principal API Architect for Layer 7
“Help people build great APIs for the Web”
 Personal Mission
“Improve the quality and usability of information on the Web.”
5

6. THE CHALLENGE
6

7. More Devices
7

8. More Apps
8

9. More APIs
9

10. The Challenge
Mobility
10

11. The Challenge
Agility
11

12. The Challenge
Mobility = Agility
12

13. The Challenge
Increase Agility
13

14. The Challenge
Maintain Stability
14

15. Lessons from the field
 Models and tools
REST and Hypermedia
 Broad Experience
SOAP, CRUD, and Hypermedia
 High-level View
The USE Paradigm
15

16. REST AND HYPERMEDIA
16

17. REST and Hypermedia
REST is an architectural model for
widely distributed systems
17

18. REST and Hypermedia - Space
http://www.flickr.com/photos/jram23/3088003105/
18

19. REST and Hypermedia - Time
http://www.flickr.com/photos/alancleaver/2661425133/
19

20. REST and Hypermedia - Model
http://www.flickr.com/photos/usnationalarchives/5476286211/
20

21. REST and Hypermedia - Tools
http://http://www.flickr.com/photos/36247316@N00/3108399560/
21

22. REST and Hypermedia
Hypermedia is a tool for
implementing remote, evolvable
systems
22

23. REST and Hypermedia - Space
http://www.flickr.com/photos/jram23/3088003105/
23

24. REST and Hypermedia - Time
http://www.flickr.com/photos/alancleaver/2661425133/
24

25. REST and Hypermedia – Evolvable
http://www.flickr.com/photos/isherwoodchris/5811756295/
25

26. REST and Hypermedia – Evolvable
http://http://www.flickr.com/photos/ecbiosheron/4139220163/
26

27. REST and Hypermedia – Evolvable
http://http://http://www.flickr.com/photos/nrg07/4735858552/
27

28. REST and Hypermedia – Real World
http://www.flickr.com/photos/smaku/233763545/
28

29. SOAP, CRUD, AND HYPERMEDIA
29

30. SOAP is for Components
http://www.flickr.com/photos/amberwalker/5755325926/
30

31. SOAP is for Components
31

32. SOAP is for Components
Strong on XML, Weak on HTTP
32

33. CRUD is for Objects
http://www.flickr.com/photos/topekalibrary/4294393624/
33

34. CRUD is for Objects
34

35. CRUD is for Objects
Strong on HTTP, Weak on Workflow
35

36. Hypermedia is for Messages
36

37. Hypermedia is for Messages
37

38. Hypermedia is for Messages
Strong on HTTP, Strong on Workflow
38

39. SOAP, CRUD, Hypermedia
Moving away from SOAP
39

40. SOAP, CRUD, Hypermedia
Implementing CRUD
40

41. SOAP, CRUD, Hypermedia
Heading toward Hypermedia
41

42. THE USE PARADIGM
42

43. Usable
Usability is the ease of use and learnability of
a human-made object.
43

44. Usable – Action Life Cycle
44

45. Usable – Focus on tasks
http://www.flickr.com/photos/somoamsterdam/4833837888/
45

46. Usable – Employ empirical measurement
46

47. Usable – Iterative design
http://www.flickr.com/photos/aajbutler/5448088057/
47

48. Usable
Focus
48

49. Usable
Measure
49

50. Usable
Iterate
50

51. Scalable
Scalability is the ability of a system, network,
or process, to handle a growing amount of
work in a capable manner.
51

52. Scalable – Out vs. Up
52

53. Scalable
http://www.flickr.com/photos/27976837@N00/4347462236/
53

54. Scalable – DevOps
http://www.flickr.com/photos/friendlydragon/3864150771/
54

55. Scalable – Where it counts
55

56. Scalable
Scale Out
56

57. Scalable
Automate
57

58. Scalable
Where it counts
58

59. Evolvable
Evolvability is defined as the capacity of a
system for adaptive change.
59

60. Evolvable
60

61. Evolvable (pandere – to stretch)
http://www.flickr.com/photos/kenjonbro/6277623578/
61

62. Evolvable (vertere – to turn)
http://www.flickr.com/photos/erdero/2274374743/
62

63. Evolvable
Versions “break”, extensions don’t.
63

64. SUMMARY
64

65. Summary - Challenge
Mobility
Agility
Stability
65

66. Summary – Models
http://www.flickr.com/photos/usnationalarchives/5476286211/
66

67. Summary – Tools
http://http://www.flickr.com/photos/36247316@N00/3108399560/
67

68. Summary – Components
http://http://www.flickr.com/photos/36247316@N00/3108399560/
68

69. Summary – Objects
http://www.flickr.com/photos/topekalibrary/4294393624/
69

70. Summary – Messages
70

71. Summary – Usable
71

72. Summary – Scalable
72

73. Summary – Evolvable
73

74. SOA and APIs:
Fearless Lessons from the Field
Mike Amundsen
Principal API Architect
@mamund
74