I could not find any documentation online that explains this integration except in the video listed above. I tried searching for d_stuff parameter in the API documentation but could find anything. Does anyone know about this integration method or if it has been deprecated or something?
The 'stuff' object contains all the cookie names (cn) and cookie values (cv | segments) from the segments mapped to cookie destinations within your AAM instance. The segments returned will be the segments the device has qualified to.
If you're looking to get traits and segments returned that the device qualified to, you can use the d_cts flag. This is not enabled by default, and you'll need to reach out to your Adobe CSM, consultant, or support to have this enabled.
Keep in mind when using d_cts that the traits and segments returned are those only on the regional Edge server on the Profile Cache Server (PCS). You'll need to wait ~12-24 hours for data in other regions or from the back-end Hbase to sync to the active PCS.