We are working on a tool that essentially allows external customers to access various extracts of our datasets, with parameterized filtering, aggregation, the usual stuff, though REST API. Some of these extracts are time consuming to prepare, so we are looking for ways to manage asynchronous report generation or making it possible for customers to schedule reports upfront, as opposed to having a synchronous API. There are tons of libraries for implementing synchronous REST APIs, but are there any standard approaches or tools for this kind of asynchronous cross-organizational communication? Like, maybe something that would allow each customer inspect their queues and schedules, configure how they want the results to be delivered? I fear we will need to build something like that from scratch.