There's a gap between what gets designed and what gets built. We've all seen it—those Figma files with perfect spacing and that one interaction that's 'probably fine to skip.' Design engineering exists in that gap.
A design engineer isn't just a designer who codes or an engineer with taste. It's someone who thinks in both languages simultaneously. Who sees a mockup and immediately thinks about state, edge cases, and how this will feel at 2x speed.
The details are the design.
I've come to believe that the last 10% of implementation is where products are won or lost. That loading state. That error message. The way the button feels when you tap it. These details rarely survive the handoff from design to engineering—unless someone is there to fight for them.
Design engineering is that fight. It's caring about craft at the code level. It's knowing that a 4px difference in padding isn't nitpicking—it's the difference between 'polished' and 'almost there.'