OYO Web Developer Interview Experience and Question

Round 1 - Profile Selection (Online)

• Write a polyfill for bind function.
• Given an expression string exp, write a program to examine whether the pairs and the orders of {,},(,),[,] are correct in exp.
  Example 1:
  Input: exp = [()]{}{[()()]()}
  Output: Balanced
  Example 2:
  Input: exp = [(])
  Output: Not Balanced
• What is the output of below program and Explain your output

for (var i = 1; i < 5; i++) {
    setTimeout(() >= console.log(i), 1000)  
}

• Write a program for debounce function.

Round 2 - DataStructure and Algorithm

• Write a program to find the intersection of two Linklist.
• Write a program to implement Forward button and Back button for browser.

Round 3 - HTML, CSS and JavaScript

• What is Doctype?
• How many types of storage we've for a Web Application?
• If there is a for loop running over some time and your browser is not responding on that particular time. What will you do to make browser available and always responding to the user?
• What is Service worker?
• What is Defer and async?
• What is box model?
• What is the difference between inline vs inline-block?
• What is the difference between absolute vs relative position?
• How can you align a div at center?
• What is the difference between svg vs canvas?
• What is pseudo-class?
• What is Javascript Hoisting?
• What is difference between function expression and function declaration?
• Closure

if(i === 1 && i === 2 && i === 3)
    console.log("yes")
else 
    console.log("no")

What will you implement i so that we always get yes?

• Write a program for sum(1)(2)
• What is the difference between forEach vs map?
• What the multiple ways to create object?
• What is the difference between Object.create vs new?
• What is the difference between Shallow copy vs Deep copy?
• Write a program for shallow compare vs deep compare?
• What is the difference between __proto__ vs prototype?
• What is the prototype chain?
• What is Prototype inheritance?
• What is Promise? Why we should have to use it instead of call back?
• What is async await?
• What is event capturing vs event bubbling?
• How to enable event capturing?
• What is the difference between prevent default vs stop propagation?
• Since both promise and setTimeout is async function which will execute first if both is available in queue at time T?
• what is job queue?
• ES6 feature - What is arrow function and when we have to use it, How it is different from normal function?

Round 4 - Design

• How to design carousal?
• How to design a search box?
• How to design a listing page like amazon?
• How to design a chat system?
• How to improve web performance and how will you optimize code?
• What is CORS issue?
• What is Modular design pattern?
• Explain about Redux architecture?
• What is Middleware?
• What is Pure component?
• What is props and can we change props value?
• How will communicate between parent to child and vice versa?

Round 5 - HR Round

• What is your role in your current team?
• Tell about any challenging work you did in the past?
• If there is 4 property in a location in one property almost 90% rooms or bed sold out but in other 3 only 10% sold out, how can you increase the sell?
• Why do you want to join Oyo?