Zalando | Senior Software Engineer(FE) | 8 YOE | SELECTED

Online Coding Test

Questions: React-Node-based application to design a search box with auto-suggestion list on every keystroke.

// Example implementation of a debouncing function in JavaScript
function debounce(func, wait) {
    let timeout;
    return function(...args) {
        clearTimeout(timeout);
        timeout = setTimeout(() => func.apply(this, args), wait);
    };
}

// Usage of debounce in a React component
import React, { useState, useEffect } from 'react';

const SearchBox = () => {
    const [query, setQuery] = useState('');
    const [suggestions, setSuggestions] = useState([]);

    useEffect(() => {
        const fetchSuggestions = debounce(async (query) => {
            // Fetch suggestions from API
            const response = await fetch(`api/suggestions?query=${query}`);
            const result = await response.json();
            setSuggestions(result);
        }, 300);

        if (query) {
            fetchSuggestions(query);
        }
    }, [query]);

    return (
        <div>
            <input 
                type="text" 
                value={query} 
                onChange={(e) => setQuery(e.target.value)} 
                placeholder="Search..." 
            />
            <ul>
                {suggestions.map((suggestion, index) => (
                    <li key={index}>{suggestion}</li>
                ))}
            </ul>
        </div>
    );
};

export default SearchBox;

Candidate's Approach

I implemented the search box with React and Node, ensuring to include the required test cases. I focused on implementing basic features, writing comprehensive unit tests, and using meaningful variable names. I also applied debouncing to optimize performance during keystrokes.

Interviewer's Feedback

No feedback provided.

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Solution Discussion | Round 1

Questions:

• What will happen if we removed imports?
• How can you optimize the application further?
• Can you write your own debouncing method?

Candidate's Approach

The interview was easygoing, focusing on my ability to explain the code I submitted. I discussed the importance of imports and potential optimizations for the application.

Interviewer's Feedback

No feedback provided.

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JavaScript Technical Interview

Questions: Specific question not provided.

Follow-up Questions:

• Topics covered included DOM Tree, CSS Specificity, JavaScript types, ES6 features, and more.

Candidate's Approach

The interview covered a wide range of JavaScript topics, allowing me to demonstrate my expertise in both fundamental and advanced concepts.

Interviewer's Feedback

No feedback provided.

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System Design

Questions: Specific question not provided.

Follow-up Questions:

• Discussed load balancing for HTTP requests and optimizing database read-write operations.

Candidate's Approach

I engaged in a discussion about system architecture, focusing on load balancing and database performance optimization strategies.

Interviewer's Feedback

No feedback provided.

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Discussion with Engineering Manager

Questions:

• What will you do immediately if your code breaks the production system?
• What will you do if you are not feeling motivated to work?
• How will you resolve team conflicts?
• What is your idea about leading a team?
• Are you comfortable working in a cross-functional team?

Candidate's Approach

This round was focused on understanding my personality and teamwork capabilities, allowing me to express my thoughts on conflict resolution and team leadership.

Interviewer's Feedback

No feedback provided.

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