Design systems are about building trust, syncing design with development, and creating clarity at scale.Lessons from Google's Material Design, Uber's Base, Shopify's Polaris, IBM's Carbon, and Atlassian's Design System.Great design systems start with a strong foundation in typography, spacing, motion, and tokens.Understanding the purpose behind a design system is crucial for its success, focusing on intent over structure.Building scalable design systems requires solid foundations, including spacing scales, typography, color systems, and tokens.Shopify's Polaris uses semantic tokens to create a shared language and scalability in design.Material Design focuses on design tokens, dynamic color systems, typography, motion, and elevation for cross-platform consistency.Effective documentation is essential for the adoption of design systems, treating it as a product to enhance usability.Documentation plays a crucial role in making design systems usable and understandable for wider adoption.Creating design systems involves understanding people, competitors, and building scalable and clear foundations that support real teams.