My slides from the "APIs and The Future of Data" session at the API Strategy & Practice conference, October 22-24 in San Francisco.

1. Data Decay and the Illusion of the Present
Dan Lynn
@danklynn

2. Keeps all your contacts in one place and keeps them
automatically up to date.
Based in Denver, Colorado
CTO & Co-Founder
dan@fullcontact.com
@danklynn

3. Let’s talk about time.

5. The Past

6. http://wearcam.org/dundas-square/2004sep23/cement.jpg

7. The Present
The Past
The Future

8. Unless you’re a yogi,
you probably can’t
even perceive the
present.

9. http://applemagazine.com/wp-content/uploads/2012/12/
exc.jpeg

10. “Traders may have gotten last week’s Fed
news 7 milliseconds early“
- Washington Post (September 24, 2013)

11. Data is always old
It’s just a question of how old.

12. How do APIs keep
data fresh?

13. Polling
GET /notifications?since=1382630675166
• Simple
• But can lead to complex scheduling
• Trades efficient use of resources for
fresh data.

14. “98.5% of polls are wasted”
- Zapier

15. Ping/Pull
• XML-RPC
• Facebook Realtime updates
• Avoids scheduled polling
• Consumer must host an endpoint
• Moderate latency (3 hops)
• Complex

16. Push
• Github service hooks
• Content of change is pushed
• Payload can be diff or full resource
• Consumer must host an endpoint
• Lowest latency (1 hop)

17. We are moving
towards a push-based
API ecosystem

18. Flight Delays
“Security is abnormally slow.”

19. Contact Information
“Dan Lynn changed his phone number”

20. Dynamic Subscriptions
POST /contacts/123/subscriptions
{
"url" : "https://.../updates?contactId=123"
}
201 Created
{ "url" : "/contacts/123/subscriptions/a3b"}

21. Dynamic Subscriptions
DELETE /contacts/123/subscriptions/a3b
200 OK

22. So which model is right
for your API?

23. What’s the cost of
acting on wrong
data?

24. $100 per contact
If left untreated
Source: SiriusDecisions

25. Low time sensitivity?
Polling is fine.

26. High time sensitivity?
Go with push.

27. APIs are combating
information asymmetry.

28. Thanks!
@danklynn
See Also:
http://xmpp.org/extensions/xep-0060.html
https://code.google.com/p/pubsubhubbub/
http://www.resthooks.org/