SDE-1 Frontend Interview Experience at Cars24 (Javascript & ReactJS)

Overview

This document provides a detailed account of a frontend engineer (SDE-1) interview experience at Cars24. The process includes assessments of JavaScript fundamentals, ReactJS practical skills, and general behavioral attributes. The structure and questions are representative of technical interviews within competitive Indian tech companies.

Interview Rounds

The interview process consisted of three rounds:

• Round 1: Core JavaScript concepts and coding.
• Round 2: ReactJS practical assignment.
• Round 3: HR and behavioral questions.

Round 1: JavaScript & Problem Solving

This round focused on fundamental JavaScript concepts. Key topics included:

1. Hoisting: The interviewer presented code snippets with variables declared using var, let, and const. The candidate was expected to predict the console output, demonstrating an understanding of variable hoisting and the Temporal Dead Zone.

   • var variables are hoisted and initialized with undefined.
   • let and const variables are hoisted but remain in the Temporal Dead Zone until their declaration is reached.

2. Implicit and Explicit Binding: The candidate was presented with scenarios involving object methods using this and the .call() method. They needed to explain how this refers to the calling context.

   • The candidate also demonstrated the behavior of arrow functions, which inherit their this value from the surrounding lexical scope.

3. Implementing a Memoize Function: The task involved creating a memoization function in JavaScript.

   • The solution involved storing previous results in an object, using serialized arguments as keys.
   • The function should return the cached result for repeated calls with identical arguments.

4. Event Loop and Output Prediction: The interviewer provided a code snippet that combined synchronous log statements, setTimeout, and a resolved Promise. The candidate was required to explain the event loop's behavior and predict the output.

   • Synchronous code executes first.
   • Microtasks (Promises) are processed before macrotasks ().