The majority of production Python web applications rely on several externally hosted application programming interfaces (APIs). APIs are also commonly referred to as third party services or external platforms. Examples include Twilio for messaging and voice services, Stripe for payment processing, and Disqus for embedded webpage comments.
There are many articles about proper API design but best practices for integrating APIs is less commonly written about. However, this subject continuously grows in importance because APIs provide critical functionality across many implementation areas.
Runscope is a service specifically designed for APIs that assists developers with automated testing and traffic inspection.
Apiary provides a blueprint for creating APIs so they are easier to test and generate clean documentation.
John Sheehan's "Zen and the Art of API Maintenance" slides are relevant for API integration.
This post on "API Driven Development" by Randall Degges explains how using APIs in your application cuts down on the amount of code you have to write and maintain so you can launch your application faster.
Safe Sex with Third Party APIs is a funny high level overview of what you should do to protect your application when relying on third party services.
My DjangoCon 2013 talk dove into "Making Django Play Nice With Third Party Services."