When I was back at Microsoft on the Office 365 team, there was a legend of sorts, apparently first uttered by our then-director, passed down by mouth to new developers. Before I write it down, it's worth noting the title progression at Microsoft: Software Engineer 1, Software Engineer 2, Senior Software Engineer, then Principal Software Engineer. It's a catchy way to remind us that software engineering is not just about solving problems, but also doing it in a way that is as simple and maintainable as possible.
SDE 1's - simple problems, complicated solutions.
SDE 2's - complicated problems, complicated solutions.
Seniors - complicated problems, simple solutions.
Principals - removes the problem altogether.