Amazon's Internal 'API Mandate'

Jeff Bezos issued a directive that all Amazon teams must expose their data and functionality through service interfaces, and communicate only via these interfaces, fostering a true Service-Oriented Architecture.

Significance

This internal mandate forced Amazon to modularize its entire infrastructure, laying the architectural and cultural groundwork that made the externalization of these services as AWS possible. It shifted thinking from monolithic applications to interconnected, reusable services.