Thanks to the collaboration between comwrap GmbH, Balance Internet and the Magento Community Engineering team, Asynchronous / Bulk API functionality was first delivered in Magento 2.3.0 as a new API that makes possible the execution of operations asynchronously using RabbitMQ (which is delivered out of the box with Magento since version 2.3.0 as well). Details and history of Asynchronous / Bulk API are described in a previous DevBlog post by Oleksandr Lyzun. In short: a user sends the same synchronous request but in response only receives a bulk_uuid. This request goes into the RabbitMQ queue and consumers in Magento process them in order. Using this bulk_uuid, users can monitor the request processing. One big benefit of bulk operations is that users can send different operations using only one request (e.g. create or update list of products).
Learn more about API design with examples from Magento 2 and MSI. API design is a crucial part of software development. This blog post delves deeper into API design, service contracts, and much more -- including Community involved for development decisions!