Reference Guide For React Checklist

React isn't hard. Your process is just messy.

I spent three years building React apps the wrong way before I figured out what actually matters. Not the hype pieces, not the trendy patterns, just the stuff that keeps your app from falling apart when someone adds a new feature. This Reference Guide For React Checklist is the result of that mess. Most people skip the boring stuff and jump straight into hooks and state management. That's why their projects rot from the inside out.

Before you write a single component

You need to know what data your app touches and where it lives. I had a project once where the state was scattered across four different contexts, two global stores, and three separate prop chains. Debugging a form submission took me six hours because I couldn't trace where the value actually changed. The fix was to draw out a simple data flow map on a whiteboard before writing anything else. One truth source per piece of data. Everything else is noise. Keep your components focused. A component should do one thing well. If you find yourself adding comments inside a component like "part 2" or "later refactor this," that's a sign it's doing too much. Split it up. What to check:

• Components under 150 lines unless there's a damn good reason
• Props defined with TypeScript interfaces, not inline objects
• No logic deeper than two levels of nesting in your JSX
• A clear separation between container and presentational components

I used to bundle API calls, data transformation, and UI rendering in the same component. It worked until the API changed and I had to trace through thirty lines of spaghetti to figure out what broke. Now I keep data fetching in custom hooks and pass the result down as props. Takes ten extra minutes to set up and saves hours later. Not everything needs a global store. Local state with useState handles most component-level concerns. If you're reaching for Zustand, Redux, or Context on day one, you're overengineering. I've seen teams slap Redux onto a CRUD app with twelve screens and maybe forty pieces of state total. That's not a solution, that's procrastination disguised as best practice. Use context for things that genuinely need to cross multiple component boundaries without prop drilling. Use local state for everything else. Use a proper store only when you have complex state interactions that local state can't handle cleanly.

Here's something most guides won't tell you: useEffect is not a data fetching tool. It's a side effect manager. Using it for fetching data creates race conditions, memory leaks, and unnecessary re-renders. I learned this the hard way when a search input fired five requests per keystroke and the results came back in random order, overwriting each other. The fix was a proper cancellation pattern with AbortController inside a useEffect that properly cleans up.

Performance that actually matters

React is fast enough for most apps without optimization. Premature optimization is where people waste their time. But there are a few things you should do by default: The biggest performance killer I see is creating objects inside the component body. Every render creates a new object, which breaks referential equality checks and forces child components to re-render. This is especially common with event handlers and style objects. Here's the actual list I go through on every project, updated version after version:

Putting business logic inside components instead of custom hooks. This makes testing nearly impossible and creates duplicate code when the same logic appears in two places. Using index as keys in lists. When items can be reordered, filtered, or deleted, index-based keys cause rendering bugs that are painful to track down. Use stable, unique identifiers. Ignoring bundle size. Tree shaking works with React when you import individual components, but default imports and certain library patterns can bloat your bundle. Check your output with webpack-bundle-analyzer or similar tools early, not after the app is shipped.

The checklist isn't meant to be exhaustive. It's a starting point. Adjust it based on your project size, team size, and requirements. A small internal tool doesn't need the same rigor as a public-facing application. But the core principles don't change: keep state predictable, keep components focused, and don't optimize before you know what's actually slow.