Really loved this interface (also cs.chromium.org) while I worked at Google. It was easy for me to orient myself, find what uses this and that, where it's being used, and then it had whole "debugging" facility:

You select your binary on borg (think kubernetes/docker), and it'll fetch from the binary with which CL (think like perforce "CL") it was built, and/or additional cherrypicked CL's, then it'll somehow go back in-time and represent how the source code looked then.

later one can (I tried it in Java, but I believe it's available for other languages too), you can inject statements right around the begining of function (a way of breakpoint), and that statement can be something like - let's log how this function was called - you were able to reference nearby statements. This could be set from the command-line, and took a bit mastery (and was bit afraid first time using it, or more like had chilling effect on me), but then my task (with 10 or 11 instances) reported these log lines, and I was able to see them in the browser.

(I have no experience with GCP, or the public face of Google Cloud, so I don't know what's available there), but this was freakin cool.