title: Options for in-memory API orchestration framework
body: <p>I have a use case to implement an <strong>in-memory orchestration framework</strong> to complete different tasks to be performed on an API call. The API call can be visualized as a list of tasks that needs to be performed when a client calls. The tasks can be visualized as a graph. </p>
  
  <p>I am currently evaluating Akka streams (graphs) to see if that solves the use-cases</p>
  
  <p><strong>Requirements for orchestration framework</strong></p>
  
  <ol>
  <li>Language support for Java or Scala.</li>
  <li>Simplicity in defining the graph or execution flow.</li>
  <li>Support for parallel tasks. The tasks can make remote REST API calls so I should be able to make parallel calls. </li>
  <li>In-memory execution of the graph. </li>
  <li>Good community support for the framework.</li>
  </ol>
  
  <p>I would like to know if there are other open source frameworks available that I can use. </p>
  
  <p>PS: I definitely do not want to re-invent the wheel by building my own. </p>