We made Claude go through a Real Tech Interview for a Senior Frontend Position

In recent months, the tech world has been abuzz with talk of Claude 3.5 Sonnet by Anthropic. With claims of advanced language understanding and problem-solving capabilities, we couldn’t help but wonder: How would Claude fare in a real-world scenario?

To satisfy our curiosity and put Claude to the test, we decided to simulate a tech interview for a senior developer position (mainly working with React) at a software house with international clients. We crafted a series of questions that a candidate might face in an interview, covering technical expertise and soft skills.

Our virtual interview panel consisted of two key figures: a Chief Technology Officer (CTO) asking in-depth technical questions, and a non-technical HR representative exploring the candidate’s interpersonal and leadership abilities.

We instructed Claude to respond as if it were a real candidate in a live conversation, aiming to assess not just its technical knowledge but also its ability to communicate complex concepts clearly and professionally. We also asked it for simple code snippets as examples.

The questions were taken from real experiences shared on the web and we also improvised a bit.

In the following article, we’ll take you through Claude’s responses to questions ranging from the intricacies of single-page applications vs. Server-Side Rendering to strategies for performance optimization in React applications. We’ll also explore how Claude handled more open-ended questions about soft skills and working in an international environment.

Can Claude.ai pass the interview for a senior frontend developer position? Let’s find out.

Tech Interview with Claude: Senior Frontend Developer candidate

Question 1: What are the main differences between SPA and SSR?

SPAs load a single HTML page and dynamically update content as the user interacts with the app. They typically use JavaScript frameworks like React or Vue.js. The main advantages are smooth user experiences and reduced server load. However, they can have slower initial load times and potential SEO challenges.

SSR, on the other hand, generates the full HTML for each page on the server. This approach offers faster initial page loads and better SEO, as search engines can easily crawl the content. However, it may result in more server load and potentially slower page transitions.

Question 2: What are Web Vitals (LCP, FID, CLS)?

Web Vitals are a set of metrics that Google considers critical for user experience:

• Largest Contentful Paint (LCP): Measures loading performance. It should occur within 2.5 seconds of when the page first starts loading.
• First Input Delay (FID): Measures interactivity. Pages should have a FID of less than 100 milliseconds.
• Cumulative Layout Shift (CLS): Measures visual stability. Pages should maintain a CLS of less than 0.1.

In the real world, these metrics guide developers in optimizing websites. For example, we might use techniques like lazy loading, code splitting, or optimizing assets to improve LCP. To enhance FID, we could minimize JavaScript execution time. For CLS, we’d ensure images and ads have reserved space to prevent layout shifts.

Is there a particular Web Vital you’d like to discuss further?

Question 3: How does React handle forms, and what are controlled components?

React handles forms through controlled components. In this approach:

• Form elements like <input>, <textarea>, and <select> maintain their own state in vanilla HTML.
• In React, we typically manage this state in the component’s state.
• We use the value prop to set the element’s value and an onChange handler to update the state when the user types.

This gives React full control over the form elements, allowing for easy manipulation and validation of user input.

Here’s a simple example:

jsxCopy<code>function NameForm() {
  const [name, setName] = useState('');

  const handleSubmit = (event) => {
    event.preventDefault();
    console.log('Submitted name:', name);
  }

  return (
    <form onSubmit={handleSubmit}>
      <input 
        type="text" 
        value={name} 
        onChange={(e) => setName(e.target.value)} 
      />
      <button type="submit">Submit</button>
    </form>
  );
}</code>Code language: JavaScript (javascript)

Would you like me to explain any part of this concept in more detail?

4) How would you Build a React app that will interact with an MLB API to display a game schedule with players, scores, dates, and broadcast stations for each game?

To build a React application that interacts with an MLB API for schedules, I would approach it like this:

1. Set up a new React project using Create React App or Next.js.
2. Create components for different parts of the UI (e.g., Schedule, Game, Team).
3. Use React Router for navigation if it’s a multi-page app.
4. Utilize React hooks, particularly useState and useEffect, for state management and side effects.
5. Use a library like Axios or fetch API to make HTTP requests to the MLB API.
6. Implement error handling and loading states for API calls.
7. Use React Context or Redux for global state management if needed.
8. Implement responsive design for various screen sizes.

Here’s a basic example of how a component might look:

jsxCopy<code>import React, { useState, useEffect } from 'react';
import axios from 'axios';

function PlayoffSchedule() {
  const [games, setGames] = useState([]);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState(null);

  useEffect(() => {
    axios.get('MLB_API_ENDPOINT')
      .then(response => {
        setGames(response.data);
        setLoading(false);
      })
      .catch(err => {
        setError(err);
        setLoading(false);
      });
  }, []);

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

  return (
    <div>
      {games.map(game => (
        <Game key={game.id} data={game} />
      ))}
    </div>
  );
}</code>Code language: JavaScript (javascript)

Would you like me to elaborate on any part of this approach?

Question 5: Yes, elaborate on your approach to performance optimization in this React application

For performance optimization in this React application, I would consider several strategies:

1. Code splitting: Use React.lazy() and Suspense to load components only when needed.
2. Memoization: Use React.memo, useMemo, and useCallback to prevent unnecessary re-renders.
3. Virtual scrolling: For long lists, implement virtualization to render only visible items.
4. Optimize images: Use appropriate formats, sizes, and lazy loading for images.
5. Minimize network requests: Use GraphQL or implement request batching if possible.
6. Implement caching: Cache API responses to reduce network requests.
7. Use production builds: Ensure you’re using minified production builds in deployment.
8. Optimize CSS: Use CSS-in-JS solutions or CSS Modules to reduce unused styles.
9. Implement proper error boundaries to prevent entire app crashes.
10. Use web workers for computationally intensive tasks to keep the main thread free.

Here’s a quick example of using React.memo and useCallback:

jsxCopy<code>import React, { useCallback, useState } from 'react';

const GameItem = React.memo(({ game, onSelectGame }) => {
  console.log('GameItem render');
  return (
    <div onClick={() => onSelectGame(game.id)}>
      {game.homeTeam} vs {game.awayTeam}
    </div>
  );
});

function GameList({ games }) {
  const [selectedGame, setSelectedGame] = useState(null);

  const handleSelectGame = useCallback((gameId) => {
    setSelectedGameId(gameId);
  }, []);

  return (
    <div>
      {games.map(game => (
        <GameItem 
          key={game.id} 
          game={game} 
          onSelectGame={handleSelectGame} 
        />
      ))}
    </div>
  );
}</code>Code language: JavaScript (javascript)

Would you like me to go into more depth on any of these optimization techniques?

The HR asks: Can you explain this last item to me in plain non-technical terms?

Certainly, I’d be happy to explain performance optimization in plain terms.

Performance optimization is like tuning up a car to make it run smoother and faster. Just as a well-tuned car uses less fuel and gets you to your destination quicker, a well-optimized website or app loads faster, responds more quickly to user actions, and uses less data and battery power.

In everyday terms, it’s about making sure that when someone uses our app:

1. It opens quickly, without long waiting times.
2. It responds immediately when they tap buttons or type something.
3. It doesn’t drain their phone battery or use up all their mobile data.
4. It works smoothly even if they have a slower internet connection.
5. It doesn’t freeze or crash, even when dealing with lots of information.

Essentially, we’re trying to create the best possible experience for our users. We want our app to be like a helpful assistant – always ready, quick to respond, and not demanding too much from the user’s device or internet connection.

It’s similar to how a restaurant might optimize its service: ensuring quick seating, prompt order-taking, efficient food preparation, and swift delivery. The goal is to make the whole experience pleasant and efficient for the customer, just as we aim to do with our app for our users.

Does this explanation help clarify the concept?

The HR asks: Which soft skills do you think you’ll need in this senior position working with an international team for big clients around the world?

Thank you for that important question. In a senior position working with an international team and big global clients, I believe several key soft skills are crucial:

1. Communication: Clear and effective communication is paramount, especially when working across different time zones and cultures. This includes being able to explain complex technical concepts in simple terms to non-technical stakeholders.
2. Adaptability: The tech world changes rapidly, and working with diverse clients means adapting to different business needs and cultural norms. Being flexible and open to change is essential.
3. Cultural sensitivity: Working with an international team and global clients requires an understanding and respect for cultural differences in communication styles, work practices, and business etiquette.
4. Leadership: As a senior developer, I’d need to guide and mentor junior team members, which requires strong leadership skills.
5. Time management: Balancing multiple projects across different time zones demands excellent time management and organizational skills.
6. Empathy: Understanding the needs and perspectives of both team members and clients is crucial for building strong relationships and delivering solutions that truly meet their needs.
7. Problem-solving: Being able to approach challenges creatively and find effective solutions, often under pressure, is a key skill in this role.
8. Collaboration: The ability to work effectively in a team, fostering a positive and productive work environment, is vital in any senior position.
9. Continuous learning: The tech field evolves rapidly, so a commitment to ongoing learning and professional development is crucial.
10. Patience and stress management: Dealing with complex projects and diverse stakeholders can be stressful, so the ability to remain calm and patient under pressure is important.

These soft skills, combined with technical expertise, would allow me to effectively lead projects, manage relationships, and deliver high-quality results in an international, client-facing environment. Would you like me to elaborate on any of these skills or how I’ve applied them in my past experiences?

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Do you think Claude is ready to become the new senior frontend developer in your company?