Event-Driven Architecture

A design system is a collection of reusable components, guidelines, and standards that ensure visual and functional consistency across a product or suite of products. It typically includes a component library, design tokens, typography rules, color palettes, and documentation. Design systems bridge the gap between designers and developers, enabling teams to build interfaces faster while maintaining a unified look and feel.

Cross-platform development is the practice of building applications that run on multiple operating systems (iOS, Android, web, desktop) from a single codebase. Frameworks like React Native, Flutter, and Kotlin Multiplatform each take different approaches — from shared UI rendering to shared business logic with native UI. The key trade-off is between code reuse efficiency and the ability to deliver platform-native experiences that feel right on each device.

A skeleton screen is a placeholder UI that mimics the page layout with simple shapes and animated gradients while content is loading. Unlike spinners, skeletons give users an immediate sense of the page structure, reducing perceived loading time. They are widely used in apps like Facebook, YouTube, and LinkedIn to create a smoother transition from loading to loaded state.

Optimistic UI is a pattern where the interface immediately reflects the expected result of a user action before the server confirms it. For example, a "like" button instantly shows the liked state while the API request happens in the background. This makes the app feel significantly faster and more responsive. If the server request fails, the UI rolls back to the previous state and notifies the user.

CSS Custom Properties (also called CSS Variables) let you define reusable values with `--my-variable` syntax and reference them anywhere using `var(--my-variable)`. Unlike preprocessor variables in Sass or Less, they are live in the browser, cascade through the DOM, and can be updated dynamically with JavaScript. They're essential for theming systems, dark mode implementations, and maintaining consistent design tokens across large stylesheets.

CI/CD (Continuous Integration / Continuous Deployment) is a set of practices that automate building, testing, and deploying code every time a developer pushes changes. Continuous Integration merges code into a shared branch frequently and runs automated tests, while Continuous Deployment automatically releases validated changes to production. Together they form the backbone of modern software delivery, reducing manual errors and accelerating release cycles.