Call Rest API -write to db - generate xml file ASYNCHRONOUSLY

I am working on a data integration project. The requirement is as follows

1) Call a rest api(GET) to get all the organizations GET /organizations

2) For eachorganization get all the networks GET /organizations/[organizationId]/networks

3) Foreach network get all the devices GET /networks/[networkId]/devices

Store all this to data in DB and create and XML file for each organization with its related network and devices. 

I know how to achieve this sequentially using Script Component in SSIS. During the initial stages this wont be a problem but as the data grows  performance will be an issue. I have limited knowledge when it comes to parallel/asynchronous programming.

Can some please help me with an efficient design solution with some samplepseudocode.

Ideally I would want to do this using SSIS but I open for any suggestions(for ex a console app)