I'm not sure that the article's distinction between "mentoring" and "coaching" matches my experience, or how I'd use the words. When I think of who has mentored me the most, it's usually the lead engineers on the teams I've worked on. In a sense they're just doing the job they're paid for, but I still consider them mentors.
To me, asking a prospective senior engineer if they're willing to mentor juniors is equivalent to asking "are you willing to put in time and effort to help juniors learn how to be better engineers?"
Yeah, I saw the terms mentor and coach being used in different and confusing ways in this thread. I figured they don't have clear meanings and that is fine. We can approximate well enough.
I imagined in-office mentoring as being something like meeting with the person for an hour or two a week, looking at the current state of their project and making comments, doing some pair programming, that sort of thing. I've received lots of informal mentoring myself in that way, so I was looking forward to doing it. But it never came up.
To me, asking a prospective senior engineer if they're willing to mentor juniors is equivalent to asking "are you willing to put in time and effort to help juniors learn how to be better engineers?"