enable self-subscription and convenient ways to learn and test the interface are critical to the  success of any API. In today’s multicloud world, it is also critical to be able to administer, catalog, and secure APIs  from a single place even if they are exposed on many different cloud endpoints, which further  simplifying the consumer’s experience. Fine-grained application integration Application-owned messaging and events In 2.4, “The three aspects of agile integration” on page 21, you explore why microservices  concepts are popular in the application space. You see how those principles can be applied to  the modernization of an integration architecture. The centralized deployment of an integration hub or ESB pattern, where all integrations are  deployed to a single, highly available (HA) pair of integration servers, has some benefits in  terms of consistency, simplicity, and efficiency. However, centralized deployment might  introduce a bottleneck for projects. Furthermore, any deployment to the shared servers runs a  risk of destabilizing existing critical interfaces because this deployment is on a single software  instance, so no individual project can choose to upgrade the version of the integration  middleware to gain access to new features without impacting others. You could break up the enterprise-wide ESB component into smaller more manageable and  dedicated pieces. Perhaps in some cases you can even get down to one run time for each  interface you expose. These  fine-grained integration deployment  patterns provide  specialized, right-sized containers for improved agility, scalability, and resilience, and are  different than the centralized ESB patterns. Asynchronous communication is even more relevant in today’s geographically separated  distributed solutions:  GLYPH<SM590000> Messaging, which was originally introduced to enable decoupled communication across  disparate platforms, continues in that mission-critical purpose, but it also now has the  same role in reliable communication across cloud boundaries.  GLYPH<SM590000> Events provide mechanisms to store an event history, which provides an alternative  source of information about data changes and enable applications to listen selectively for  notifications, and build local data stores suited to their needs. However, it is no longer acceptable to wait on a highly specialized team to provision an  asynchronous communication infrastructure. Teams must be able to self-provision and  configure queues and topics for immediate use as part of their event-driven integration  projects.  Templated and patternized mechanisms must be introduced to simplify provisioning tasks,  and where possible provide them in as  in-place  multi-tenant managed services. The queue  and topic configurations must be application-owned so that they can produce prototypes and  iterate on solutions rapidly. 