The document discusses best practices for app developers using APIs. It recommends starting by understanding the presentation tier requirements and finding APIs to meet them. It warns that issues like authentication, authorization and cross-origin resource sharing will be encountered. It suggests using a proxy to work around blockers and move technical logic from the presentation tier to prevent bloat. The proxy should also be monitored for bloat, moving business logic behind APIs when needed. Non-functional requirements should be consolidated at the proxy rather than individual APIs.