This document discusses the impact of microservices architecture on API management. It describes how microservices are structured as independently deployable services that communicate over a network. When microservices communicate across organizational boundaries, API management is advised to provide capabilities like a gateway, developer portal, and API management. The document also discusses how a service mesh can be used for internal microservice communication within an organization, making API management optional in that context. It provides examples of how Istio implements a service mesh and its features for dynamic routing and traffic control between microservices without requiring code changes.