🚀 React Interview Experience(August 2025): SimForm

Overview

This document outlines a React developer interview experience at SimForm in August 2025. The interview process assessed the candidate's knowledge of React concepts, asynchronous JavaScript, and testing methodologies. The following sections detail the specific questions and expected answers, providing a valuable resource for individuals preparing for similar frontend engineering roles.

Interview Rounds

The interview covered a range of topics, including:

• Asynchronous Data Loading: The candidate was questioned on how to handle asynchronous data loading in React applications using useEffect and useState hooks, along with libraries such as axios. The interviewer expected the candidate to demonstrate understanding of managing loading and error states.

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

function DataFetcher() {
  const [data, setData] = useState([]);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState(null);

  useEffect(() => {
    axios.get('https://jsonplaceholder.typicode.com/posts')
      .then(response => setData(response.data))
      .catch(err => setError(err))
      .finally(() => setLoading(false));
  }, []);

  if (loading) return <p>Loading...</p>;
  if (error) return <p>Error: {error.message}</p>;

  return (
    <ul>
      {data.map(post => <li key={post.id}>{post.title}</li>)}
    </ul>
  );
}

• Programmatic Navigation with React Router: The candidate was asked about navigating programmatically in React Router, with emphasis on the useNavigate hook (v6+). The expected answer involved using the hook to navigate to specific routes in response to events or API calls.

import { useNavigate } from 'react-router-dom';

function MyComponent() {
  const navigate = useNavigate();

  const handleClick = () => {
    // Navigate to /dashboard programmatically
    navigate('/dashboard');
  };

  return <button onClick={handleClick}>Go to Dashboard</button>;
}

• Localization in React Applications: Questions were posed regarding localizing React applications using i18n libraries like react-i18next. The candidate needed to describe how to store translations, detect user locales, and use translation hooks or components.

import { useTranslation } from 'react-i18next';

function App() {
  const { t, i18n } = useTranslation();

  const changeLanguage = (lang) => i18n.changeLanguage(lang);

  return (
    <div>
      <p>{t('welcome_message')}</p>
      <button onClick={() => changeLanguage('en')}>English</button>
      <button onClick={() => changeLanguage('fr')}>French</button>
    </div>
  );
}