Cloud Development

Question 1

What is a “service principal”? How is different than a “service account”?

Answer 1

Service principal specific to Microsoft, used to identify an application within Azure. Used to authenticate, authorize using other Azure resources.

Service account is a more general term for any non-human identity.

Question 2

In terms of software development, what is an “artifact”?

Answer 2

A tangible output or byproduct of the software development process. (.exe, .dll [libraries], .zip [packages], config files, etc.)

Question 3

In terms of software development, what is an “agent”?

Answer 3

Computing infrastructure that runs one job at a time (physical machine or virtual machine). Required to use when teams want an automatic build, test, and deploy process.

Question 4

What is a blue green deployment?

Answer 4

An application release model that gradually transfers user traffic from a previous version of an app or microservice to a nearly identical new release.

([source])(https://www.redhat.com/en/topics/devops/what-is-blue-green-deployment)

Question 5

What does MERN stand for?

Answer 5

MongoDB, Express.js, React.js, Node.js

Question 6

Describe the role of each component in the MERN stack.

Answer 6

MongoDB: Database
Express.js: Backend framework
React.js: Frontend library
Node.js: Runtime environment

Question 7

What is a Single Page Application (SPA)?

Answer 7

A web application that loads a single HTML page and dynamically updates content without full page reloads.

Question 8

What is the flow of data in a MERN application?

Answer 8

Client (React) -> Server (Express/Node) -> Database (MongoDB) -> Server (Express/Node) -> Client (React)

Question 9

What is an API?

Answer 9

Application Programming Interface. A set of rules that defines how applications communicate.

Question 10

What is RESTful API?

Answer 10

An architectural style for designing networked applications, using HTTP methods (GET, POST, PUT, DELETE) for data manipulation.

Question 11

What type of database is MongoDB?

Answer 11

NoSQL, document-oriented database.

Question 12

What is a document in MongoDB?

Answer 12

A data structure composed of field-value pairs, similar to JSON objects.

Question 13

What is a collection in MongoDB?

Answer 13

A grouping of MongoDB documents.

Question 14

What is the purpose of _id in MongoDB?

Answer 14

A unique identifier for each document.

Question 15

What is a schema in MongoDB (conceptually, as it’s schema-less)?

Answer 15

The structure and organization of documents within a collection, specifying fields, their data types, and validation rules.

Question 16

What is a query in MongoDB?

Answer 16

An operation that retrieves data from a collection based on specified criteria.

Question 17

What is an aggregation pipeline in MongoDB?

Answer 17

A series of data processing stages used to transform and analyze data.

Question 18

What is Mongoose?

Answer 18

An Object Data Modeling (ODM) library for MongoDB and Node.js.

Question 19

What is the purpose of Express.js?

Answer 19

A fast, minimalist web framework for Node.js, providing a robust set of features for handling HTTP requests, middleware, and routing

Question 20

What is middleware in Express.js?

Answer 20

Functions that have access to the request object (req), the response object (res), and the next middleware function in the application’s request-response cycle.

Question 21

What is a route in Express.js?

Answer 21

A section of Express.js code that associates an HTTP request with a specific function.

Question 22

What are the HTTP methods (verbs) used in RESTful APIs?

Answer 22

GET, POST, PUT, DELETE, PATCH.

Question 23

What is req.body?

Answer 23

The parsed body of the HTTP request, typically containing data sent from the client.

Question 24

What is res.send()?

Answer 24

An Express.js method used to send a response to the client.

Question 25

What is res.json()?

Answer 25

An Express.js method used to send a JSON response to the client.

Question 26

What is res.status()?

Answer 26

An Express.js method used to set the HTTP status code of the response.

Question 27

What is a route parameter?

Answer 27

A variable part of a URL path in Express.js (e.g., /users/:id).

Question 28

What are query parameters?

Answer 28

Key value pairs added to the end of a URL after a question mark.

Question 29

What is React.js?

Answer 29

A JavaScript library for building user interfaces.

Question 30

What is a component in React.js?

Answer 30

A reusable piece of UI.

Question 31

What is JSX?

Answer 31

JavaScript XML, a syntax extension for JavaScript that allows you to write HTML-like code in React.

Question 32

What are props in React.js?

Answer 32

Properties passed from parent components to child components.

Question 33

What is state in React.js?

Answer 33

Data that can change within a component, triggering re-renders.

Question 34

What are React Hooks?

Answer 34

Functions that let you 'hook into' React state and lifecycle features from function components.

Question 35

What is useState?

Answer 35

A React Hook that lets you add state to function components.

Question 36

What is useEffect?

Answer 36

A React Hook that lets you perform side effects in function components.

Question 37

What is useContext?

Answer 37

A React Hook that lets you consume context values.

Question 38

What is the virtual DOM?

Answer 38

A lightweight copy of the actual DOM, used by React to efficiently update the UI.

Question 39

What is React Router?

Answer 39

A library that enables navigation between different views in a React SPA.

Question 40

What is Node.js?

Answer 40

A JavaScript runtime built on Chrome's V8 JavaScript engine, enabling server-side execution of applications.

Question 41

What is npm (Node Package Manager)?

Answer 41

A package manager for JavaScript and Node.js.

Question 42

What is package.json?

Answer 42

A file that contains metadata about a Node.js project, including dependencies.

Question 43

What is require()?

Answer 43

A function used to import modules in Node.js.

Question 44

What are modules in Node.js?

Answer 44

Reusable blocks of code that can be imported and used in other files.

Question 45

What is asynchronous programming?

Answer 45

A programming paradigm that allows multiple operations to run concurrently without blocking each other.