Monzo Senior Backend Developer Interview Questions and Answers

Q1. What is Node Js
Ans. 
Node.js is a runtime environment that allows you to run JavaScript code outside of a web browser.
• Node.js is built on Chrome's V8 JavaScript engine.

• It uses an event-driven, non-blocking I/O model that makes it lightweight and efficient.

• Node.js is commonly used for building server-side applications and APIs.

• It has a large ecosystem of open-source libraries and frameworks, such as Express.js.
Answered by AI
Add your answer
Q2. What is middleware
Ans. 
Middleware is a software component that acts as a bridge between an application's request and response.
• Middleware functions have access to the request and response objects

• They can modify the request and response objects

• Middleware can be used for tasks like authentication, logging, error handling, etc.
Answered by AI
Add your answer
Q3. What is promise
Ans. 
A promise is an object representing the eventual completion or failure of an asynchronous operation.
• Promises are used to handle asynchronous operations in JavaScript.

• They can be in one of three states: pending, fulfilled, or rejected.

• Promises can be chained using .then() to handle success and .catch() to handle errors.

• Example: new Promise((resolve, reject) => { setTimeout(() => resolve('Done!'), 1000); });
Answered by AI
Add your answer
Q4. What is promise.all
Ans. 
promise.all is a method in JavaScript that takes an array of promises and returns a single promise that resolves when all of the input promises have resolved.
• Used to handle multiple asynchronous operations at once

• Returns a single promise that resolves when all input promises have resolved

• If any of the input promises is rejected, the returned promise is rejected with the reason of the first rejected promise
Answered by AI
Add your answer
Q5. What is callback
Ans. 
A callback is a function passed as an argument to another function to be executed later.
• Callbacks are commonly used in asynchronous programming to handle tasks that take time to complete.

• They are often used in event handling, timers, and AJAX requests.

• Callbacks can be synchronous or asynchronous, depending on when they are executed.

• Example: setTimeout(callback, 1000) will execute the callback function after 1 second.
Answered by AI
Add your answer

Array,Tree, Behaviour questions 2 hr duration easy-medium

Q1. Array Traversal using topological sort algorithm
Ans. 
Topological sort can be used to traverse an array of strings in a specific order.
• Topological sort is used to order elements based on their dependencies.

• In the context of array traversal, we can use topological sort to determine the order in which strings should be processed.

• For example, if strings represent tasks and their dependencies, we can use topological sort to ensure tasks are executed in the correct order.
Answered by AI
Add your answer
Q2. Right most node in almost complete bst
Ans. 
The rightmost node in an almost complete binary search tree is the last node in the last level of the tree.
• In an almost complete binary search tree, all levels are completely filled except possibly for the last level, which is filled from left to right.

• To find the rightmost node, start at the root and traverse the tree by always going to the right child until reaching the last level.

• The rightmost node will be the last
Answered by AI
Add your answer

Q1. Introduce yourself
Ans. 
I am a passionate Backend Developer with 5 years of experience in building scalable and efficient web applications.
• 5 years of experience in backend development

• Proficient in programming languages like Java, Python, and Node.js

• Strong understanding of database management systems such as MySQL and MongoDB

• Experience in developing RESTful APIs and microservices

• Familiar with cloud technologies like AWS and Azure
Answered by AI
Add your answer
Q2. Some python programs
Add your answer

Q1. React questions
Add your answer
Q2. Nodejs questions
Add your answer

Q1. About current project , oops concepts, solid principles, java 8 coding questions
Add your answer
Q2. Hashmap , hashmap internal implementation
Add your answer

Q1. Find pairs from list whose is equals to target
Ans. 
Find pairs from list whose sum is equal to target
• Iterate through the list and for each element, check if the target minus the element exists in a hashmap

• If it exists, add the pair to the result list

• If it doesn't exist, add the current element to the hashmap
Answered by AI
Add your answer
Q2. Multiple iNheritance
Add your answer