Cars24 SDE-2 Frontend Interview Experience

Overview

This document outlines a candidate's experience during a frontend SDE-2 interview at Cars24. The interview process was structured into multiple rounds, assessing the candidate's technical skills, problem-solving abilities, and understanding of frontend development principles.

Interview Rounds

The interview process consisted of three rounds:

Round 1: Technical Interview

This round focused on core JavaScript concepts and problem-solving skills. The candidate was asked the following questions:

1. Closure: The candidate was questioned on JavaScript closures, providing an explanation and code example:

   function closure() {
       let count = 0;
       return function test() {
           count++;
           return count;
       }
   }
   
   const closuredTest = closure();
   
   console.log(closuredTest());
   console.log(closuredTest());
   console.log(closuredTest());
   

2. Currying: The candidate was asked to explain currying and create a curried version of the given function:

   function sum(a, b, c){ return a + b + c; }
   function curry(fn){
     return function curriedFn(...params){
       if(params.length >= fn.length){
         return fn(...params);
       }
       else{
         return function(...next){
           return curriedFn(...params,...next);
         }
       }
     }
   }
   
   let curriedSum = curry(sum);
   
   console.log(curriedSum(1, 2, 3));
   console.log(curriedSum(1)(2,3));
   console.log(curriedSum(1)(2)(3));
   

3. Task Queue & Event Loop: The candidate explained the concepts of the Task Queue and Event Loop, supplementing the explanation with the following code snippet:

   console.log('start');
   
   setTimeout(() => {
       console.log('mid');
   }, 0);
   
   for (let i = 0; i < 100000; i++) {
       console.log('thread blocking code');
   }
   console.log('end');
   

4. Output-Based Question: The candidate was presented with an output-based question involving async/await and Promises:

   async function async1() {
       console.log("async1 start");
       const data = await async2();
       console.log(data);
       console.log("async1 end");
   }
   
   async function async2() {
       console.log("async2");
       return "async2 completed";
   }
   
   console.log("script start");
   
   setTimeout(function () {
       console.log("setTimeout");
   }, 0);
   
   async1();
   
   new Promise(function (resolve) {
       console.log("promise1");
       resolve();
   }).then(function () {
       console.log("promise2");
   });
   
   console.log("script end");