How would you establish a modular typographic scale for a design system?

This tests your ability to build systematic typography with contextual decisions rather than arbitrary values. A strong answer covers four decisions in order: first, selecting the ratio by contrast needs—higher for marketing pages, lower for dashboards; second, rounding values and pruning scale to only needed sizes; third, adding extra small sizes when the scale lacks sizes for dense UIs; fourth, varying base font size across breakpoints. A red flag is defaulting to a ratio for every project without analyzing content density or device context.