Swiftui Guideline: Layout — Use LazyVStack LazyHStack for lists. Description: Lazy loading for performance. Do: Lazy stacks for long lists. Don't: Regular stacks for 100+ items. Good Example: LazyVStack { ForEach(items) }. Bad Example: VStack { ForEach(largeArray) }. Severity: High. Docs: https://developer.apple.com/documentation/swiftui/lazyvstack.