how to run multiple ready api composite projects in parallel ?

so my use case: 

1.   The app I am testing is based on microservices architecture. Currently we have around 35 services (this will increase)that have to be tested.
2.    So we have 35 separate ready api composite projects that have tests.
3.    We want to run regression any time there is a change in the app, and want to minimize the time to run regression.

So I want to explore the option of running composite projects in parallel.

Thanks