It also entirely depends on your career path. Mine didn't involve programming outside of shell for most of it, and involved tons of deep expertise on a variety of topics.

I was shocked doing an interview in my last round and got so many test questions. I bombed so hard because it wasn't what I was doing.

The real key to me is, we treat all of these jobs as more or less the same, when in reality they are all vastly different. There is no singular senior engineer skill set, but a variety.