Moving from "writing React components" to "architecting React applications." We cover the reconciliation process, scalable patterns, and state management strategies.
React is not just a UI library; it's a state-synchronization engine. Understanding the Virtual DOM and Reconciliation is key to optimizing performance.
React calls your components, compares the result with the previous render (diffing), and calculates necessary changes. This is pure JS and fast.
React applies those calculated changes to the actual DOM. This is expensive and where we typically see performance bottlenecks.
Scalable React relies on Composition over Inheritance. We break complex UIs into smaller, focused parts.
Focus on how things look. They receive data via props and have no dependencies on global stores.
Focus on how things work. They fetch data, manage state, and pass it down to presentational components.
Compound Components: Think of the HTML <select> and
<option> tags. They work together to share state implicitly. We can replicate
this pattern in React Context.
Not everything belongs in Redux. Modern architecture splits state into three categories:
Lifting State Up: If two components need the same data, move the state to their closest common ancestor.
Stop grouping files by type (`/components`, `/hooks`). Start grouping by Feature (`/features/auth`, `/features/cart`). This is known as Colocation.
High-quality resources for this module: