That was a lot of fun for a while, but it was pretty clear that I needed to get in front of projects, rather than behind them, to have any useful impact on new products. Also, I hit a couple of home runs: Creating the architectures for a couple of successful products because nobody else wanted to learn the theory. So I was invited to have a more front-end role.
This led to a new informal definition of "systems engineer." I've become the person who understands how products work in their entirety, when it requires synthesizing knowledge from multiple disciplines. I create and test the theory of operation. This is a good use for physicists in industry, by the way. Physics research, especially in small labs, is multidisciplinary. We don't really have any of our own techniques, so we constantly borrow from others. My graduate research involved optics, electronics, programming, mechanics, and data analysis. In fact, I've dropped the "systems engineer" title, and am now a "scientist."
Today, I'm at a level where I am much more focused on onboarding and development of junior colleagues. I'm also finding and developing talent within the organization for people who might like to have more of a systems role. It is a hard role to fill, because engineers tend to specialize -- perhaps for good reason based on job markets. And if traditional engineers get good enough at coding to do it for money, they get sucked up by the software industry.