Grab (India) Senior Software Engineer Interview Questions and Answers

Q1. What is event loop, how it works.
Ans. 
Event loop is a mechanism in programming that allows for asynchronous execution of code by continuously checking for and handling events.
• Event loop is commonly used in JavaScript to handle asynchronous operations like setTimeout, setInterval, and AJAX requests.

• It works by continuously checking the event queue for any pending events, executing them one by one, and then moving on to the next event.

• Event loop helps in pre...read more
Answered by AI
Add your answer
Q2. Micro task queue and macro task queue.
Add your answer
Q3. Is node.js single threaded or multi-threaded, also discuss threadpool and it's usages.
Add your answer
Q4. Tell the order of output, among process, promise, setTimeout, fs, setInterval.
Ans. 
The order of output is fs, process, setTimeout, setInterval, promise.
• fs module is synchronous and will output first

• process is next in line

• setTimeout will be executed after process

• setInterval will be executed after setTimeout

• promise will be executed last
Answered by AI
Add your answer

Q1. JavaScript usages compiler or interpreter.
Ans. 
JavaScript is an interpreted language.
• JavaScript is an interpreted language, meaning it is executed line by line at runtime.

• There is no separate compilation step in JavaScript like in languages that use compilers.

• Examples of interpreted languages include Python, Ruby, and PHP.
Answered by AI
Add your answer
Q2. Tell the output among various for loops using var, let and bind.
Ans. 
Output comparison of for loops using var, let, and bind in JavaScript.
• Using var: variable is function-scoped, may lead to unexpected behavior in loops.

• Using let: variable is block-scoped, recommended for loop iterations.

• Using bind: creates a new function with a specified 'this' value and initial arguments.
Answered by AI
Add your answer
Q3. A medium level dsa question on array, solved it using pre-sum.
Add your answer
Q4. Situation based question, on how to pick a suitable database.
Add your answer

Q1. What do you do on daily basis, and how to decide a tech-stack on high level.
Ans. 
I work on coding, debugging, testing, and collaborating with team members. Tech stack decisions are based on project requirements, scalability, performance, and team expertise.
• Daily tasks include coding, debugging, testing, and collaborating with team members

• Tech stack decisions are based on project requirements, scalability, performance, and team expertise

• Consider factors like language compatibility, libraries/framewo...read more
Answered by AI
Add your answer
Q2. Design an online scalable, real-time document sharing application like google docs.
Ans. 
Design a scalable, real-time document sharing app like Google Docs.
• Use websockets for real-time collaboration

• Implement version control to track changes

• Utilize a distributed database for scalability

• Include user authentication and access control

• Support offline editing with automatic sync
Answered by AI
Add your answer
Q3. How to handle images also in the future.
Ans. 
Utilize cloud storage for scalability, implement image compression techniques, and regularly update image processing libraries.
• Utilize cloud storage for scalability

• Implement image compression techniques

• Regularly update image processing libraries
Answered by AI
Add your answer
Q4. Any other way to solve the problem, of high I/O on same document to overcome throughput and conflicts.
Add your answer

Questions were crayon box ,the bot and the game and happy neighbourhood for 90 mins

Q1. Array basics was asked
Add your answer
Q2. Segment tree,prefix sum
Add your answer

Q1. Low level design was asked
Add your answer

Q1. Design Booking Management System
Ans. 
Design a Booking Management System for handling reservations and scheduling.
• Create a user-friendly interface for customers to make bookings

• Implement a database to store booking information

• Include features for managing availability, cancellations, and payments
Answered by AI
Add your answer

DSA Problems from leetcode

Q1. Basics about Android and iOS
Add your answer

Q1. House robber problem
Ans. 
House robber problem involves finding the maximum amount of money that can be stolen without alerting the police.
• Use dynamic programming to keep track of the maximum amount of money that can be stolen at each house.

• At each house, the robber can either choose to rob the current house and the one before the previous house, or skip the current house.

• Keep track of the maximum amount of money that can be stolen at each hous
Answered by AI
View 1 more answer
Q2. Solid principles
Add your answer
Q3. Garbage collection
Add your answer

I was asked question on sliding window on finding the largest subarray with all distinct numbers. The interviewer was very helpful.

Q1. Leetcode medium coding question
Add your answer

Q1. Push notifications
Add your answer
Q2. DATA STRUCTURE with js
Ans. 
Data structures are used to store and organize data in a computer so that it can be accessed and manipulated efficiently.
• Data structures in JavaScript include arrays, objects, sets, and maps.

• Arrays are used to store a collection of elements, accessed by index.

• Objects are used to store key-value pairs.

• Sets are used to store unique values.

• Maps are used to store key-value pairs with keys of any type.
Answered by AI
Add your answer

Q1. Timer in react native
Ans. 
In React Native, timers can be implemented using the setTimeout and setInterval functions.
• Use setTimeout for a one-time delay before executing a function.

• Use setInterval for executing a function repeatedly at a specified interval.

• Remember to clear the timer using clearTimeout or clearInterval when no longer needed.
Answered by AI
Add your answer
Q2. Find occurance of elements in array
Ans. 
Count occurrences of elements in an array of strings
• Iterate through the array and use a hashmap to store the count of each element

• Use a for loop to go through each element and increment the count in the hashmap

• Return the hashmap with element counts
Answered by AI
Add your answer