> e.g. hook in a senior engineer that you know is intimate with the system.
unless, of course, you don't know said engineer because you don't even work in the same company, you're a just a user seeing a problem in an app you use
Or they work in a different part of the fairly-large company that you both work for.
I guess emmelaich either missed the part of my commentary where I talked about handling inter-organization communication, and/or has never worked at a company where it's simply impossible to know everyone who could reasonably be relevant to the stuff that the company works on.
At least triage it with your best effort.