Assigning default applications to a group

I have 4 apps, but I have about 10,000 groups. I need to assign default applications to each group.

How can I do this?

Will each group have a different set of applications t should be assigned? Have you looked into using the /Apps endpoint to assign a given group to a given app?

When you say default, do you mean that these groups should simply be assigned the appropriate applications, or are you trying to do something else as well?