The Importance of Lightweight Tasks
One of the corollaries of embracing microservices is the increased need to aggregate information from multiple remote sources. In turn, exploiting every opportunity to execute such operations in parallel becomes more important and managing the resulting complexities becomes more central to the organization of your code. There are several core Java language and library options available to achieve this, but their generality makes them relatively low-level for this purpose: they lack a task abstraction.
A task in this context is a class that performs a non-trivial, track-worthy unit of work in an execution graph, potentially comprised of many such tasks. Tasks are important because interacting with an external system or database often involves details that are best encapsulated in a separate class. Done well, this separation of concerns facilitates refactoring at a logical level without impedance from the particular complexities involved with any external interaction. Such refactoring is to be expected as business goals evolve – which is one of the reasons for embracing microservices in the first place.