Kanerika | Frontend Developer | September 2025 | 3.5 YOE

Explain your comprehensive knowledge about React, covering its core concepts, lifecycle, state management, and ecosystem.

Describe the React reconciliation process, including the Virtual DOM, diffing algorithm, and how React updates the actual DOM efficiently.

Detail your experience working with React class components. When did you use them, and what are their characteristics?

From a modern React development perspective, explain why it's still beneficial for a React developer to understand class components.

List and briefly describe the various React Hooks you have utilized in your projects.

Explain the key distinctions between React's useEffect and useMemo hooks, including their primary use cases and how they impact performance.

Explain what npm (Node Package Manager) is, its primary purpose, and how it's used in web development.

Describe nvm (Node Version Manager) and its utility for managing multiple Node.js versions on a single machine.

Explain the concept of a JavaScript Promise, what problem it solves, and its role in asynchronous programming.

Distinguish between Promise.all and Promise.allSettled in JavaScript, including their behavior when one or more promises reject.

Provide pseudocode for creating a JavaScript Promise that resolves successfully after a delay of 2 seconds.

Given the following JavaScript code snippet involving a Promise and setTimeout, determine the exact order of console outputs:

const myPromise = new Promise((resolve) => {
    console.log("Log 1");
    setTimeout(() => {
        console.log("Log 2");
        resolve("Promise Resolved in 2 Secs");
        console.log("Log 3");
    }, 2000)
    console.log("Log 4");
})
myPromise.then((value) => console.log(value))

Analyze the following JavaScript loop and determine its output. Pay attention to the 'break' and 'return' statements:

for(let i=0;i<10;i++) {
    if(i == 5)
        break;
    if(i == 2)
        return;
    console.log(i);
}

Given the JavaScript destructuring assignment:

const [a,b, ...c] = [1]
console.log(a);
console.log(b);
console.log(c);

Predict the values that will be logged to the console for a, b, and c.

Write JavaScript code to flatten a deeply nested object into a single-level object, preserving keys by concatenating them with a delimiter (e.g., dot notation).

Explain the concept of a Higher-Order Component (HOC) in React, its purpose, and how it's typically implemented.

Share a practical example of a Higher-Order Component (HOC) you have implemented or encountered in your own development experience, and explain its benefits.

Describe what React Custom Hooks are, their primary purpose, and how they contribute to code reusability and organization.

Compare and contrast React's Higher-Order Components (HOCs) and Custom Hooks, highlighting their similarities, differences, and when to use each.

Write a CSS media query that applies a background color of 'red' when the viewport width is greater than 700 pixels AND less than 1000 pixels.

Discuss the different libraries or tools you have used for integrating APIs in your web development projects (e.g., Axios, Fetch API, etc.).

Explain the concept of Micro-Frontend architecture, including its benefits, challenges, and typical use cases in large-scale web applications.

Describe strategies and techniques you would employ to effectively handle or prevent stale API calls in a frontend application.

Provide a brief introduction about yourself, highlighting your professional background, key skills, and career aspirations.

Elaborate on your most recent project, covering its objectives, your specific role and responsibilities, the technology stack used, any challenges encountered and how you overcame them, and your key contributions to its success.

Discuss various techniques and best practices you would use to optimize the performance of a React application.

Explain your approach to designing and structuring React applications to ensure modularity, reusability of components, and scalability for future growth.

Compare and contrast Redux and Zustand, two popular state management libraries for React, highlighting their core principles, API, and use cases.

Explain the fundamental differences between React.js (client-side rendering) and Next.js (a React framework with server-side rendering capabilities), including their respective strengths and use cases.

Describe your strategies for balancing the mentorship of junior developers and ensuring high code quality, all while adhering to tight project deadlines.

Provide an example of a time you experienced conflict among team members. Explain the situation, your role in it, and how you contributed to its resolution.

Explain your process for managing situations where client or stakeholder requirements are vague or ambiguous, ensuring clarity and successful project outcomes.

Outline your step-by-step approach to handling a critical production issue reported by a client or stakeholder, from initial assessment to resolution and communication.

Explain the distinctions between null and undefined in JavaScript, including their types, origins, and common use cases.

Define what a closure is in JavaScript. Provide a clear code example to illustrate its concept and utility.

Explain what an anonymous function is in JavaScript and where it is typically used.

Taking a previous example of a closure, demonstrate how to rewrite or integrate it using an anonymous function.

Describe what an IIFE (Immediately Invoked Function Expression) is in JavaScript. Provide a code example demonstrating its syntax and purpose.

Explain the concept of Higher-Order Functions (HOFs) in JavaScript, emphasizing their role in functional programming.

Provide several common examples of Higher-Order Functions that are built-in or frequently used in JavaScript (e.g., map, filter, reduce).

Provide pseudocode that mimics the functionality of JavaScript's Array.prototype.reduce() method.

Describe your approach and best practices for gracefully handling null or undefined values that might be received from an API response in your frontend application.

Following up on handling null/undefined API responses, explain how you would replace these values with a default or alternative value when necessary.

List and briefly explain the various data types available in JavaScript (primitive and non-primitive).

Explain why it is possible to use methods like push() and pop() to modify an array that has been declared using the const keyword in JavaScript.

Define what a Promise is in JavaScript and explain the historical context or problems it was introduced to solve in asynchronous programming.

Explain the concept of currying in JavaScript, including what it is and its benefits.

Describe what Web Workers are in the context of web development, and explain their primary purpose and benefits for improving application performance.

Explain the concept of prototypes and the prototype chain in JavaScript, and how they relate to inheritance.

Compare and contrast traditional function declarations/expressions with arrow functions in JavaScript, highlighting key differences like this binding, arguments object, and syntax.

Provide a comprehensive explanation of the this keyword in JavaScript, detailing its dynamic binding behavior in various contexts (global, function, method, constructor, arrow functions).

Define NaN (Not-a-Number) in JavaScript. Explain common scenarios or operations that result in NaN.

What is the result of typeof NaN in JavaScript?

Determine the output of the following JavaScript expression:

console.log(NaN === NaN)

What is the result of typeof null in JavaScript? Explain this peculiar behavior.