I'd take systems that were permitted to have filtered egress at this point. The lion's share of my work is in networking, so network segmentation is the "hammer" I pick up first.
Vendors gnash teeth and complain when I ask for their app's dependencies on hosted APIs and off-site resources. In the environments where I'm mandated to maintain FBI CJIS compliance I can still hold vendors accountable and get what I want. It's pretty much a lost battle in every other environment and unfiltered egress to the Internet from servers is just expected.
That's not even to get into the topic of communication flow within an application. >sigh<