OAuth: Authorization code flow vs. client credential flow

[Bernd Schickerbauer]

I am digging the documentation to understand the capabilities of OAuth applications / integrations.

I do understand that you can integrate with Atlassian products with OAuth apps with authorization code flow, which means by its definition that you need to have user-context available (interactive sign-in). For instance, user does a sign-in on a web page which is redirecting the user to get the auth code and proper access token.

But how are integrations designed which support a system-to-system process? Processes where user context is not available? PAT is definitely not be the preferred option from an enterprise perspective as it is using basic auth protocol, which you want to avoid actually.

What is the best-practice for system-to-system communication with modern auth protocols? I am looking for sth. like a client-credential flow which supports non-interactive processes.