Devship Mern Full Stack Developer Interview Questions and Answers

React hooks are functions that let you use state and other React features in functional components.

• Allow functional components to have state and lifecycle methods

• Replace class components with simpler functional components

• Examples: useState, useEffect, useContext

Redux is a predictable state container for JavaScript apps, used to manage application state in a centralized store.

• Redux helps manage the state of an application in a predictable way

• It allows for a single source of truth for the state of the application

• Redux is commonly used with React to manage the state of components

• Actions are dispatched to update the state in Redux store

• Reducers specify how the state changes in re...read more

Yes, I have experience with file upload tasks. Files are saved in DB by storing the file path and retrieval is done by fetching the file path from the DB.

• Used multer middleware in Node.js to handle file uploads

• Saved file path in MongoDB using Mongoose schema

• Retrieved file by querying the database for the file path

• Implemented file upload functionality in a project using React for the front end

CRUD operations in MongoDB include create, read, update, and delete operations on documents in a collection.

• Create: db.collection.insertOne()

• Read: db.collection.find()

• Update: db.collection.updateOne()

• Delete: db.collection.deleteOne()

Aggregation is the process of combining data from multiple sources to provide a summary or overview.

• Aggregation in databases involves grouping and summarizing data to provide insights.

• In MongoDB, aggregation pipelines are used to process data and return computed results.

• Examples of aggregation functions include sum, average, count, and group by.

They are used in MongoDB aggregation pipeline to perform various operations like joining, filtering, projecting, etc.

• Used in MongoDB aggregation pipeline for data manipulation

• Perform operations like joining, filtering, projecting, etc.

• Help in combining data from multiple collections

• Use $lookup to perform a left outer join between two collections

Developed a real-time chat application using Node.js with Socket.io for instant messaging functionality.

• Implemented server-side logic using Node.js to handle incoming messages and broadcast them to all connected clients

• Utilized Socket.io library to establish WebSocket connections for real-time communication

• Integrated with MongoDB to store chat messages and user information

• Implemented authentication and authorization me...read more

I have worked on various MERN stack projects, focusing on building scalable web applications with a strong emphasis on user experience.

• E-commerce Platform: Developed a full-featured e-commerce application using MongoDB for the database, Express.js for the server, React for the frontend, and Node.js for the backend.

• Real-Time Chat Application: Created a real-time chat application utilizing Socket.io for instant messaging...read more