What design patterns do you use (DRY, SOLID, GRASP, etc.)?

In my work on the frontend, I adhere to the following patterns and principles:

• DRY (Don't Repeat Yourself) — avoid code duplication, extract repeating parts into functions or components.
• SOLID — especially useful when building complex components and services:
  • Single Responsibility for separating logic.
  • Open/Closed for extendability without modifying existing code.
• GRASP — used to define object responsibilities, for example, choosing controllers to manage state.
• Design Patterns — often use:
  • Module for organizing code.
  • Observer for subscribing to events.
  • Factory for creating components with different configurations.

Example of using the Observer pattern in React:

import React, { useState, useEffect } from 'react';

function useEventEmitter(emitter, eventName) {
  const [data, setData] = useState(null);

  useEffect(() => {
    function handler(eventData) {
      setData(eventData);
    }
    emitter.on(eventName, handler);
    return () => {
      emitter.off(eventName, handler);
    };
  }, [emitter, eventName]);

  return data;
}

This approach helps write maintainable and scalable code.