As products and teams grow larger, ensuring your UI has a consistent design becomes a difficult problem. Components often are meant to be composed in specific ways, and violating these implicit invariants can create an inconsistent user experience. Code review can catch these invariant violations, but relying on reviews for this kind of feedback is both slow and unnecessarily burdensome to the reviewer. In this talk, we'll explore how you can use type systems to enforce your invariants in order to create a more consistent UI.