How do frontend systems integrate with APIs, analytics, and design systems?

Frontend systems integrate with APIs through structured data fetching using REST or GraphQL, with libraries like Axios or the native Fetch API handling requests and React Query or SWR managing caching, loading states, and error handling. API responses are then bound to UI components, making the interface dynamic without page reloads. Authentication tokens are managed securely using HTTP-only cookies or secure storage patterns to prevent XSS vulnerabilities.

Analytics integration is managed through Google Tag Manager as the container, with GA4 events, Meta Pixel, and custom conversion tracking fired based on user interactions defined in the frontend code. Design system integration connects the coded component library to the Figma design system through shared design tokens, ensuring that color, typography, and spacing values stay synchronized between design and production. Tools like Style Dictionary automate the transformation of Figma tokens into CSS variables or JavaScript constants used directly in the frontend codebase.