ReactJS is one of the most popular libraries to create dynamic, interactive user interfaces. A React developer has to maintain their acquaintance with the best practices, tools, or innovative approaches to help them in getting the best out of their applications with high performance and maintenance. Here are the five top lessons every ReactJS developer should adopt to refine their operations, push their app's performance, and stay ahead.

1. Get Completely on Board with React Hooks
Introduced by React 16.8, Hooks have completely modified the way developers handle state and side effects inside functional components. Some of the hooks used are useState, useEffect, useContext, and custom hooks. They let you create cleaner and more modular code potentially, doing away with the need for class components. Here is all the reason that you have to get onboard for sure:

Easier For State Management: Hooks provide a much cleaner approach to handle local component state instead of a class component.
Simple Logic Reusability: You can create custom hooks to encapsulate logic that you can reuse across your components without writing the same code over and over again.
Readability at its Best: After being linked with the modern ES6+ syntax, codes written with hooks always have better readability and become way easier for debugging.
Pro Tip: If you still haven't created custom hooks, try building them for common operations-like getting data from an API or processing form submissions.

2. Use TypeScript with React
TypeScript provides helpful features to make React-applications more type-safe and maintainable, better for many developers. Use TypeScript to:
Catch Errors at Compile Time: Catch the stupid type errors before they become live, and let TypeScript take care of it.
Get Better Tooling: TypeScript works well with modern IDEs and has better autocompletion, documentation, and refactoring support.
Help with Communication: With TypeScript, using typed interfaces, any communication about how to structure and pass props can be more effective when working in teams.
Bonus Tip: Even if you are going to use TypeScript for the first time, start introducing it gradually into your existing React projects, particularly when it comes to props and state definitions in components.

3. Optimize Component Performance with React.memo and useCallback
React apps slow down as their size in terms of apps increases, particularly when components unnecessarily re-render themselves. React distributes various tools such as React.memo and useCallback for rendering optimization purposes:
React.memo: This is a higher-order component that checks props on functional components and prevents them from re-rendering unless and until the props have changed. Any time props are not changed, re-rendering is prevented, and performance increases tremendously.
useCallback: It allows memorizing callbacks in order to prevent the recreation of a function on each render cycle while mainly useful for function passing to props.
Bonus Tip: It is worthy to make a React.memo of components that do not need to re-render often and optimally useCallback to deal with complex prop trees when optimization assignments come into play.

4. Apply Code Splitting and Lazy Loading
This technique will prove to be beneficial regarding optimizing Load Performance while developing large-scale React applications and ensuring the best user experience. In the code splitting method, the initial load times improve by loading only the necessary code when required. These methods include:

Code Splitting: Tools like Webpack or Parcel to split your code into smaller independent bundles that can load.Once again independently.
React.lazy and Suspense: React uses their built-in React.lazy() and Suspense components for lazy loading the components; this can result in an increased amount of loading performance at the beginning.
Pro Tip: Try to lazy-load the routes and components that will not be immediately needed, such as admin panels or seldomly visitedpages.

5. Use ESLint and Prettier for Code Quality
Clean, consistent, and bug-free code will be needed for long-term viability for any React project. They are there to help enforce coding standards and automate your code formatting:

ESLint: It is one of the great tools to catch any syntax error and enforce a consistent style code in your JS codebase.
Prettier: A code formatting tool that works with ESLint, more of an opinionated one but consistent enough in style.
Pro Tip: Make sure to configure your ESLint and Prettier in a way that includes any style guide that your team identifies with, like Airbnb'sReact/JSX Style Guide, to keep a clean and collaborative codebase.