A look at common API styles available today, a look back at historical API styles, and guidance for selecting the right API styles for your organization. Deep-dive of HTTP, mentioned in the presentation, can be found at: http://bit.ly/power-http

1. Are REST APIs Still Relevant Today?
13 June 2018 @ Austin API Summit
James Higginbotham
@LaunchAny

2. 2
Introduction
• API Strategy, Program Execution, Training
– API design
– Microservices
– Containerization
• Recent Projects
– Enterprise IT
– SaaS
– From 100s to 10s of thousands of developers
– Variety of verticals

4. 4
APIs Solve a Variety of Use Cases
Customer
Experience
Worker
Experience
Supplier/Partner
Experience

5. 5
APIs Offer Different Interaction Styles
Request/
Response
Request/
Acknowledge
Batch
Publish/
Subscribe
Message
Streaming

6. 6
APIs: Looking Back at History

7. 7
The Road So Far…
1990s
RPC & Distributed
Object Integration

8. 8
CORBA Architecture

9. 9
The Road So Far…
1990s
RPC & Distributed
Object Integration
2000s
Corp-to-Corp
Integration

10. 10
SOAP Protocol Support: Tunneling through HTTP, SMTP, JMS
Source: https://stackoverflow.com/questions/15705892/what-is-the-purpose-of-ws-addressing

11. 11
SOAP w/ Asynchronous Callbacks
Source: https://docs.oracle.com/cd/E15523_01/web.1111/e15184/asynch.htm

12. 12
The Road So Far…
1990s
RPC & Distributed
Object Integration
2000s
Corp-to-Corp
Integration
2010s
+
Mobile/Data
Integration

13. 13
The Power of the HTTP Protocol for APIs

14. 14
The Basics: URLs, Headers, and HTTP Methods
Method Safe
(Side-
Effect?)
Idempotent
GET Yes Yes
POST No No
PUT No Yes
PATCH No No
DELETE No Yes
HEAD Yes Yes

15. 15
Content Negotiation: Supporting Multiple Content Types
GET https://api.example.com/projects HTTP/1.0
Accept: application/json;q=0.5,application/xml;q=1.0
HTTP/1.0 200 OK
Date: Tue, 16 June 2015 06:57:43 GMT
Content-Type: application/xml
<project>…</project>
15

16. 16
Language Negotiation: Supporting Multiple Languages
GET https://api.example.com/projects HTTP/1.0
Accept-Language: en;q=0.5,de;q=1.0
HTTP/1.0 200 OK
Date: Tue, 16 June 2015 06:57:43 GMT
Content-Language: en
<project>
<status>active</status>
<status-display>active</status-display>
</project> 16

17. 17
Language Negotiation: Supporting Multiple Languages
GET https://api.example.com/projects HTTP/1.0
Accept-Language: en;q=0.5,de;q=1.0
HTTP/1.0 200 OK
Date: Tue, 16 June 2015 06:57:43 GMT
Content-Language: de
<project>
<status>active</status>
<status-display>angenommen</status-display>
</project> 17

18. 18
Client-Side Caching: Improving App Performance
Source: https://developers.google.com/web/fundamentals/performance/optimizing-content-efficiency/http-caching

19. 19
Intermediary Caching: Reducing Network Latency with Proxies and CDNs
Source: https://www.maxcdn.com/one/visual-glossary/proxy-caching/

20. 20
Conditional Requests: Staying Up-to-date
Source: https://developer.mozilla.org/en-US/docs/Web/HTTP/Conditional_requests

21. 21
Concurrency Control: Protecting Resource Integrity with Optimistic Locking
Source: https://developer.mozilla.org/en-US/docs/Web/HTTP/Conditional_requests

22. 22
“The Power of HTTP for APIs”
2-part series:
http://bit.ly/power-http

23. 23
A Look at Today’s Common API Styles

24. 24
Popular API Styles in 2018

25. 25
GraphQL Example: POST query
Source: https://blog.octo.com/en/graphql-a-new-actor-in-the-api-world/

26. 26
Advantages of GraphQL
Hierarchical
Data Support
Field-Level
Selection
Strong Typing
Good Fit for
Front-End APIs
Introspection

27. 27
Challenges for Some GraphQL Implementors
Limited Endpoint
Security Enforcement
Limited
Ops Tooling
Inconsistencies in
Recommendations
Lack of Flexibility
for Content Types
Lack of
Cacheability

28. 28
Popular API Styles in 2018

29. 29
gRPC: Example Service Definition, Server, and Client
Source: https://grpc.io/docs/quickstart/node.html

30. 30
Advantages of gRPC
High Performance/
Low Latency
Protobuf
Message Format
Code Generation
(client and server)
Bi-Directional
Communication
Built On
HTTP/2

31. 31
Challenges for Some gRPC Implementors
Limited
Error Handling
Limited
Dev/Ops Tooling
Inconsistent Code Gen
Across Languages
Lack of Flexibility
for Content Types
Lack of
Cacheability

32. 32
Popular API Styles in 2018

33. 33
REST APIs are stuck in the land of CRUD

34. 34
Revisiting the REST Constraints
Client-Server Stateless Cache Layered System
Code on Demand
(optional)
Uniform Interface
(resources, representations,
hypermedia)

35. 35
Deep-Dive: REST’s Layered and Cache Constraints
Logging
AccessManagement
RateLimiting
Caching
Custom
APIImplementation
LoadBalancer
CDN/EdgeCache
Client
Network Infra API Management Layer Your Code
Client
Cache
HTTP HTTP HTTP HTTP

36. 36
HTTP HTTP HTTP
Operationalizing Your API: There is more to your API than code!
Logging
AccessManagement
RateLimiting
Caching
Custom
APIImplementation
LoadBalancer
CDN/EdgeCache
Client
Network Infra API Management Layer Your Code
Client
Cache
HTTP

37. When APIs Meet Jobs-To-Be-Done
{
…
"_links": {
“self": {"href": "/approval-requests/d796f2d0eb72492bb088"},
“approve": {"href": "/approval-requests/d796f2d0eb72492bb088/approve"},
“decline": {"href": "/approval-requests/d796f2d0eb72492bb088/decline"},
},
…
}

38. 38
Popular API Styles in 2018

39. 39
Webhooks, SSE, and Message Streaming

40. 40
Some Things Change, But Some Stay the Same
+

41. 41
Are REST APIs Still Relevant?

42. 42
Yes!

43. 43
Yes!
Yes, and…

44. 44
#1: We must spend time to
understand the business
problem first, not the
technology

45. 45
#2: We all must become better
educated with what HTTP has
to offer, rather than reinventing
the HTTP protocol over-and-
over (then tunneling it via
HTTP)

46. 46
#3. Evolve our tools and
frameworks to better take
advantage of HTTP:
caching, concurrency control,
hypermedia

47. 47
#4. Our thinking must move
”beyond code on the laptop”
and into business use cases,
ops, compliance, and support
concerns

48. 48
#5. Stop using ‘vs.’ and start
using ‘and’ when it comes to
selecting API styles

49. 49
Moving the Mindset From “vs.” to “and”
+
+ +
+ +

50. James Higginbotham
james@launchany.com
@launchany
https://apideveloperweekly.com
Thank you