[Talking about double-lenticular cartography:] I was thinking of this for the Big Wall though, not for the mouse. In particular, being able to scroll the pages left and right by leaning your body left and right (like the film thing that RMO put on the big wall for Silent Night), but also being able to shoot a laser beam to the smoosh to jump to a position. So, relative movement with your body, and absolute movement with your hand.

It’s one of the reasons why senior engineers are worth their salaries. Not just because they write good code (which they often do!), but because they derisk projects. They turn “I don’t even know what this is” into “there are two small projects and one thing we should cut.” And you know what’s funny? When senior engineers do this well, it looks easy. Like nothing was even done. The project just… goes smoothly. Fewer surprises, production fires, or emergency meetings. But what actually happened was that someone did a lot of invisible work upfront.

People love to describe senior engineers with a big checklist: architecture, communication, ownership, leadership, etc. But if you strip away the title, the salary, and the years of experience, there’s one core skill that separates senior+ engineers from everyone else: reducing ambiguity. Everything else flows from that.