β
Frontend Frameworks Interview Q&A β Part 2 ππΌ
1οΈβ£ What is Virtual DOM in React?
Answer:
The Virtual DOM is a lightweight copy of the real DOM. React updates it first, calculates the difference (diffing), and then efficiently updates only what changed in the actual DOM.
2οΈβ£ Explain data binding in Angular.
Answer:
Angular supports one-way, two-way (
3οΈβ£ What is JSX in React?
Answer:
JSX stands for JavaScript XML. It allows you to write HTML-like syntax inside JavaScript, which is compiled to Reactβs
4οΈβ£ What are slots in Vue.js?
Answer:
Slots allow you to pass template content from parent to child components, making components more flexible and reusable.
5οΈβ£ What is lazy loading in Angular or React?
Answer:
Lazy loading is a performance optimization technique that loads components or modules only when needed, reducing initial load time.
6οΈβ£ What are fragments in React?
Answer:
7οΈβ£ How do you lift state up in React?
Answer:
By moving the shared state to the closest common ancestor of the components that need it, and passing it down via props.
8οΈβ£ What is a watch property in Vue?
Answer:
9οΈβ£ What is dependency injection in Angular?
Answer:
A design pattern where Angular provides objects (like services) to components, reducing tight coupling and improving testability.
π What is server-side rendering (SSR)?
Answer:
SSR renders pages on the server, not the browser. It improves SEO and load times. Examples: Next.js (React), Nuxt.js (Vue), Angular Universal.
π¬ Tap β€οΈ for more!
1οΈβ£ What is Virtual DOM in React?
Answer:
The Virtual DOM is a lightweight copy of the real DOM. React updates it first, calculates the difference (diffing), and then efficiently updates only what changed in the actual DOM.
2οΈβ£ Explain data binding in Angular.
Answer:
Angular supports one-way, two-way (
[(ngModel)]), and event binding to sync data between the component and the view.3οΈβ£ What is JSX in React?
Answer:
JSX stands for JavaScript XML. It allows you to write HTML-like syntax inside JavaScript, which is compiled to Reactβs
createElement() calls.4οΈβ£ What are slots in Vue.js?
Answer:
Slots allow you to pass template content from parent to child components, making components more flexible and reusable.
5οΈβ£ What is lazy loading in Angular or React?
Answer:
Lazy loading is a performance optimization technique that loads components or modules only when needed, reducing initial load time.
6οΈβ£ What are fragments in React?
Answer:
<React.Fragment> or <> lets you group multiple elements without adding extra nodes to the DOM.7οΈβ£ How do you lift state up in React?
Answer:
By moving the shared state to the closest common ancestor of the components that need it, and passing it down via props.
8οΈβ£ What is a watch property in Vue?
Answer:
watch allows you to perform actions when data changes β useful for async operations or side effects.9οΈβ£ What is dependency injection in Angular?
Answer:
A design pattern where Angular provides objects (like services) to components, reducing tight coupling and improving testability.
π What is server-side rendering (SSR)?
Answer:
SSR renders pages on the server, not the browser. It improves SEO and load times. Examples: Next.js (React), Nuxt.js (Vue), Angular Universal.
π¬ Tap β€οΈ for more!
β€2
β
Backend Basics Interview Questions β Part 1 (Node.js)π§ π»
π 1. What is Node.js?
A: Node.js is a runtime environment that lets you run JavaScript on the server side. It uses Googleβs V8 engine and is designed for building scalable network applications.
π 2. How is Node.js different from traditional server-side platforms?
A: Unlike PHP or Java, Node.js is event-driven and non-blocking. This makes it lightweight and efficient for I/O-heavy operations like APIs and real-time apps.
π 3. What is the role of the
A: It stores metadata about your project (name, version, scripts) and dependencies. Itβs essential for managing and sharing Node.js projects.
π 4. What are CommonJS modules in Node.js?
A: Node uses CommonJS to handle modules. You use
π 5. What is the Event Loop in Node.js?
A: It allows Node.js to handle many connections asynchronously without blocking. Itβs the heart of Nodeβs non-blocking architecture.
π 6. What is middleware in Node.js (Express)?
A: Middleware functions process requests before sending a response. They can be used for logging, auth, validation, etc.
π 7. What is the difference between
A:
-
-
-
π 8. What is a callback function in Node.js?
A: A function passed as an argument to another function, executed after an async task finishes. Itβs the core of async programming in Node.
π 9. What are Streams in Node.js?
A: Streams let you read/write data piece-by-piece (chunks), great for handling large files. Types: Readable, Writable, Duplex, Transform.
π 10. What is the difference between
A:
-
-
π¬ Tap β€οΈ for more!
π 1. What is Node.js?
A: Node.js is a runtime environment that lets you run JavaScript on the server side. It uses Googleβs V8 engine and is designed for building scalable network applications.
π 2. How is Node.js different from traditional server-side platforms?
A: Unlike PHP or Java, Node.js is event-driven and non-blocking. This makes it lightweight and efficient for I/O-heavy operations like APIs and real-time apps.
π 3. What is the role of the
package.json file? A: It stores metadata about your project (name, version, scripts) and dependencies. Itβs essential for managing and sharing Node.js projects.
π 4. What are CommonJS modules in Node.js?
A: Node uses CommonJS to handle modules. You use
require() to import and module.exports to export code between files.π 5. What is the Event Loop in Node.js?
A: It allows Node.js to handle many connections asynchronously without blocking. Itβs the heart of Nodeβs non-blocking architecture.
π 6. What is middleware in Node.js (Express)?
A: Middleware functions process requests before sending a response. They can be used for logging, auth, validation, etc.
π 7. What is the difference between
process.nextTick(), setTimeout(), and setImmediate()? A:
-
process.nextTick() runs after the current operation, before the next event loop. -
setTimeout() runs after a minimum delay. -
setImmediate() runs on the next cycle of the event loop.π 8. What is a callback function in Node.js?
A: A function passed as an argument to another function, executed after an async task finishes. Itβs the core of async programming in Node.
π 9. What are Streams in Node.js?
A: Streams let you read/write data piece-by-piece (chunks), great for handling large files. Types: Readable, Writable, Duplex, Transform.
π 10. What is the difference between
require and import?A:
-
require is CommonJS (used in Node.js by default). -
import is ES6 module syntax (used with "type": "module" in package.json).π¬ Tap β€οΈ for more!
β
Backend Basics Interview Questions β Part 2 (Express.js Routing) ππ§
π 1. What is Routing in Express.js?
A: Routing defines how your application responds to client requests (GET, POST, etc.) to specific endpoints (URLs).
π 2. Basic Route Syntax
π3. Route Methods
-
-
-
-
π 4. Route Parameters
π 5. Query Parameters
π 6. Route Chaining
π 7. Router Middleware
π 8. Error Handling Route
π‘ Pro Tip: Always place dynamic routes after static ones to avoid conflicts.
π¬ Tap β€οΈ if this helped you!
π 1. What is Routing in Express.js?
A: Routing defines how your application responds to client requests (GET, POST, etc.) to specific endpoints (URLs).
π 2. Basic Route Syntax
app.get('/home', (req, res) => {
res.send('Welcome Home');
});π3. Route Methods
-
app.get() β Read data -
app.post() β Create data -
app.put() β Update data -
app.delete() β Delete data π 4. Route Parameters
app.get('/user/:id', (req, res) => {
res.send(req.params.id);
});π 5. Query Parameters
app.get('/search', (req, res) => {
res.send(req.query.keyword);
});π 6. Route Chaining
app.route('/product')
.get(getHandler)
.post(postHandler)
.put(putHandler);π 7. Router Middleware
const router = express.Router();
router.get('/about', (req, res) => res.send('About Page'));
app.use('/info', router); // URL: /info/about
π 8. Error Handling Route
app.use((req, res) => {
res.status(404).send('Page Not Found');
});π‘ Pro Tip: Always place dynamic routes after static ones to avoid conflicts.
π¬ Tap β€οΈ if this helped you!
β€1
β
Backend Basics Interview Questions β Part 3 (Express.js Middleware) ππ§
π 1. What is Middleware in Express.js?
A: Middleware are functions that execute during the request-response cycle. They can modify
π 2. Types of Middleware
- Application-level: Applied to all routes or specific routes
- Router-level: Applied to router instances
- Built-in: e.g.,
- Third-party: e.g.,
π 3. Example β Logging Middleware
π 4. Built-in Middleware
π 5. Router-level Middleware
π 6. Error-handling Middleware
π 7. Chaining Middleware
π‘ Pro Tip: Middleware order matters β always place error-handling middleware last.
π¬ Tap β€οΈ for more!
π 1. What is Middleware in Express.js?
A: Middleware are functions that execute during the request-response cycle. They can modify
req/res, execute code, or end the request.π 2. Types of Middleware
- Application-level: Applied to all routes or specific routes
- Router-level: Applied to router instances
- Built-in: e.g.,
express.json(), express.static() - Third-party: e.g.,
cors, morgan, helmetπ 3. Example β Logging Middleware
app.use((req, res, next) => {
console.log(`req.method{req.url}`);
next(); // Pass to next middleware/route
});π 4. Built-in Middleware
app.use(express.json()); // Parses JSON body
app.use(express.urlencoded({ extended: true })); // Parses URL-encoded body
π 5. Router-level Middleware
const router = express.Router();
router.use((req, res, next) => {
console.log('Router Middleware Active');
next();
});
π 6. Error-handling Middleware
app.use((err, req, res, next) => {
console.error(err.stack);
res.status(500).send('Something broke!');
});π 7. Chaining Middleware
app.get('/profile', authMiddleware, logMiddleware, (req, res) => {
res.send('User Profile');
});π‘ Pro Tip: Middleware order matters β always place error-handling middleware last.
π¬ Tap β€οΈ for more!
β
Backend Basics Interview Questions β Part 4 (REST API) ππ»
π 1. What is a REST API?
A: REST (Representational State Transfer) APIs allow clients to interact with server resources using HTTP methods like GET, POST, PUT, DELETE.
π 2. Difference Between REST & SOAP
- REST uses HTTP, is lightweight, and supports JSON/XML.
- SOAP is protocol-based, heavier, uses XML, and has strict standards.
π 3. HTTP Methods
-
-
-
-
-
π 4. Example β Creating a GET Route
π 5. Example β POST Route
π 6. Route Parameters & Query Parameters
π 7. Status Codes
- 200 β OK
- 201 β Created
- 400 β Bad Request
- 404 β Not Found
- 500 β Server Error
π 8. Best Practices
- Validate request data
- Handle errors properly
- Use consistent endpoint naming
- Keep routes modular using
π¬ Double Tap β€οΈ for more!
π 1. What is a REST API?
A: REST (Representational State Transfer) APIs allow clients to interact with server resources using HTTP methods like GET, POST, PUT, DELETE.
π 2. Difference Between REST & SOAP
- REST uses HTTP, is lightweight, and supports JSON/XML.
- SOAP is protocol-based, heavier, uses XML, and has strict standards.
π 3. HTTP Methods
-
GET β Read data -
POST β Create data -
PUT β Update data -
DELETE β Delete data -
PATCH β Partial update π 4. Example β Creating a GET Route
app.get('/users', (req, res) => {
res.send(users); // Return all users
});π 5. Example β POST Route
app.post('/users', (req, res) => {
const newUser = req.body;
users.push(newUser);
res.status(201).send(newUser);
});π 6. Route Parameters & Query Parameters
app.get('/users/:id', (req, res) => {
res.send(users.find(u => u.id == req.params.id));
});
app.get('/search', (req, res) => {
res.send(users.filter(u => u.name.includes(req.query.name)));
});π 7. Status Codes
- 200 β OK
- 201 β Created
- 400 β Bad Request
- 404 β Not Found
- 500 β Server Error
π 8. Best Practices
- Validate request data
- Handle errors properly
- Use consistent endpoint naming
- Keep routes modular using
express.Router() π¬ Double Tap β€οΈ for more!
β
Backend Basics Interview Questions β Part 5 (Error Handling) ππ»
π 1. What is Error Handling?
A: Error handling is the process of catching and responding to errors that occur during request processing, ensuring the server doesnβt crash and clients get meaningful messages.
π 2. Built-in Error Handling
- Express automatically catches errors in synchronous routes.
- Example:
π 3. Custom Error-handling Middleware
- Middleware with 4 parameters
π 4. Try-Catch in Async Functions
- Async route handlers need try-catch to handle errors.
π 5. Sending Proper Status Codes
- 400 β Bad Request
- 401 β Unauthorized
- 403 β Forbidden
- 404 β Not Found
- 500 β Internal Server Error
π 6. Error Logging
- Use
π 7. Best Practices
- Keep error messages user-friendly.
- Donβt expose stack traces in production.
- Centralize error handling.
- Validate inputs to prevent errors early.
π¬ Tap β€οΈ for more!
π 1. What is Error Handling?
A: Error handling is the process of catching and responding to errors that occur during request processing, ensuring the server doesnβt crash and clients get meaningful messages.
π 2. Built-in Error Handling
- Express automatically catches errors in synchronous routes.
- Example:
app.get('/error', (req, res) => {
throw new Error('Something went wrong!');
});π 3. Custom Error-handling Middleware
- Middleware with 4 parameters
(err, req, res, next) handles errors globally. app.use((err, req, res, next) => {
console.error(err.stack);
res.status(500).send({ message: err.message });
});π 4. Try-Catch in Async Functions
- Async route handlers need try-catch to handle errors.
app.get('/async', async (req, res, next) => {
try {
const data = await getData();
res.send(data);
} catch (err) {
next(err);
}
});π 5. Sending Proper Status Codes
- 400 β Bad Request
- 401 β Unauthorized
- 403 β Forbidden
- 404 β Not Found
- 500 β Internal Server Error
π 6. Error Logging
- Use
console.error() or logging libraries like winston or morgan for debugging.π 7. Best Practices
- Keep error messages user-friendly.
- Donβt expose stack traces in production.
- Centralize error handling.
- Validate inputs to prevent errors early.
π¬ Tap β€οΈ for more!
β€3
β
Databases Interview Questions & Answers πΎπ‘
1οΈβ£ What is a Database?
A: A structured collection of data stored electronically. Examples: MySQL, MongoDB, PostgreSQL.
2οΈβ£ Difference between SQL and NoSQL
- SQL: Relational, structured tables, uses schemas, supports ACID transactions.
- NoSQL: Non-relational, flexible schema, document/graph/column storage, scalable.
3οΈβ£ What is a Primary Key?
A: Unique identifier for a record in a table. Example:
4οΈβ£ What is a Foreign Key?
A: A field in one table that refers to the primary key of another table to maintain relationships.
5οΈβ£ CRUD Operations
- Create:
- Read:
- Update:
- Delete:
6οΈβ£ What is Indexing?
A: A performance optimization technique to speed up data retrieval. Types: B-Tree, Hash indexes.
7οΈβ£ What is Normalization?
A: Process of organizing tables to reduce redundancy and improve data integrity. Forms: 1NF, 2NF, 3NF, BCNF.
8οΈβ£ What is Denormalization?
A: Combining tables or duplicating data to improve read performance at the cost of redundancy.
9οΈβ£ ACID Properties
- Atomicity: All or nothing transaction
- Consistency: Database remains valid
- Isolation: Transactions donβt interfere
- Durability: Committed changes persist
π Difference between JOIN types
- INNER JOIN: Only matching rows
- LEFT JOIN: All left + matching right rows
- RIGHT JOIN: All right + matching left rows
- FULL OUTER JOIN: All rows from both tables
1οΈβ£1οΈβ£ What is a NoSQL Database?
A: Database designed for large-scale, unstructured, or semi-structured data. Types: Document (MongoDB), Key-Value (Redis), Column (Cassandra), Graph (Neo4j).
1οΈβ£2οΈβ£ What is a Transaction?
A: A set of SQL operations executed as a single unit of work. Either all succeed or all fail.
1οΈβ£3οΈβ£ Difference between DELETE and TRUNCATE
- DELETE: Row-by-row, can use WHERE, slower, logs each row.
- TRUNCATE: Removes all rows, faster, cannot use WHERE, resets auto-increment.
1οΈβ£4οΈβ£ What is a View?
A: A virtual table representing a stored query. Useful for abstraction, security, and complex queries.
1οΈβ£5οΈβ£ Difference between SQL and ORM
- SQL: Direct queries to DB
- ORM: Object-Relational Mapping, allows interacting with DB using programming language objects (e.g., Sequelize, SQLAlchemy)
π¬ Tap β€οΈ if you found this useful!
1οΈβ£ What is a Database?
A: A structured collection of data stored electronically. Examples: MySQL, MongoDB, PostgreSQL.
2οΈβ£ Difference between SQL and NoSQL
- SQL: Relational, structured tables, uses schemas, supports ACID transactions.
- NoSQL: Non-relational, flexible schema, document/graph/column storage, scalable.
3οΈβ£ What is a Primary Key?
A: Unique identifier for a record in a table. Example:
id column in Users table. 4οΈβ£ What is a Foreign Key?
A: A field in one table that refers to the primary key of another table to maintain relationships.
5οΈβ£ CRUD Operations
- Create:
INSERT INTO table_name ... - Read:
SELECT * FROM table_name ... - Update:
UPDATE table_name SET ... WHERE ... - Delete:
DELETE FROM table_name WHERE ... 6οΈβ£ What is Indexing?
A: A performance optimization technique to speed up data retrieval. Types: B-Tree, Hash indexes.
7οΈβ£ What is Normalization?
A: Process of organizing tables to reduce redundancy and improve data integrity. Forms: 1NF, 2NF, 3NF, BCNF.
8οΈβ£ What is Denormalization?
A: Combining tables or duplicating data to improve read performance at the cost of redundancy.
9οΈβ£ ACID Properties
- Atomicity: All or nothing transaction
- Consistency: Database remains valid
- Isolation: Transactions donβt interfere
- Durability: Committed changes persist
π Difference between JOIN types
- INNER JOIN: Only matching rows
- LEFT JOIN: All left + matching right rows
- RIGHT JOIN: All right + matching left rows
- FULL OUTER JOIN: All rows from both tables
1οΈβ£1οΈβ£ What is a NoSQL Database?
A: Database designed for large-scale, unstructured, or semi-structured data. Types: Document (MongoDB), Key-Value (Redis), Column (Cassandra), Graph (Neo4j).
1οΈβ£2οΈβ£ What is a Transaction?
A: A set of SQL operations executed as a single unit of work. Either all succeed or all fail.
1οΈβ£3οΈβ£ Difference between DELETE and TRUNCATE
- DELETE: Row-by-row, can use WHERE, slower, logs each row.
- TRUNCATE: Removes all rows, faster, cannot use WHERE, resets auto-increment.
1οΈβ£4οΈβ£ What is a View?
A: A virtual table representing a stored query. Useful for abstraction, security, and complex queries.
1οΈβ£5οΈβ£ Difference between SQL and ORM
- SQL: Direct queries to DB
- ORM: Object-Relational Mapping, allows interacting with DB using programming language objects (e.g., Sequelize, SQLAlchemy)
π¬ Tap β€οΈ if you found this useful!
β
Authentication & Security β Web Development Interview Questions & Answers ππ‘οΈ
1οΈβ£ What is the difference between Authentication and Authorization?
Answer:
- Authentication verifies who the user is (e.g., login).
- Authorization controls what the user can access (e.g., admin vs user access).
2οΈβ£ What is JWT (JSON Web Token)?
Answer:
A compact token used for stateless authentication. It contains a header, payload (user info), and signature to verify data integrity.
3οΈβ£ How is JWT more secure than traditional sessions?
Answer:
JWTs are stored on the client-side and signed with a secret. Unlike sessions, they donβt require server-side storage, making them scalable and tamper-evident.
4οΈβ£ What's the difference between Cookies and LocalStorage?
Answer:
- Cookies: Automatically sent with each HTTP request, smaller in size, can be
- LocalStorage: Larger, persists longer, not sent with requests (manual access only).
5οΈβ£ What is CORS? Why is it important?
Answer:
CORS (Cross-Origin Resource Sharing) is a browser mechanism that restricts requests from different origins. It protects against unwanted cross-site access.
6οΈβ£ What is CSRF and how do you prevent it?
Answer:
CSRF (Cross-Site Request Forgery) tricks a logged-in user into submitting unwanted actions.
Prevention: Use CSRF tokens,
7οΈβ£ What is XSS and how do you prevent it?
Answer:
XSS (Cross-Site Scripting) injects malicious scripts into web pages.
Prevention: Escape user input, use Content Security Policy (CSP), and sanitize HTML.
8οΈβ£ What is HTTPS and why is it critical?
Answer:
HTTPS encrypts data using SSL/TLS. It ensures data privacy, integrity, and trust between client and server.
9οΈβ£ How do you implement password security in web apps?
Answer:
- Store hashed passwords using bcrypt or Argon2
- Use salting
- Enforce strong password rules
- Implement rate-limiting on login attempts
π What is OAuth?
Answer:
OAuth is an authorization protocol that allows users to grant access to third-party apps without sharing credentials (e.g., login with Google/Facebook).
π¬ Tap β€οΈ if you found this useful!
1οΈβ£ What is the difference between Authentication and Authorization?
Answer:
- Authentication verifies who the user is (e.g., login).
- Authorization controls what the user can access (e.g., admin vs user access).
2οΈβ£ What is JWT (JSON Web Token)?
Answer:
A compact token used for stateless authentication. It contains a header, payload (user info), and signature to verify data integrity.
3οΈβ£ How is JWT more secure than traditional sessions?
Answer:
JWTs are stored on the client-side and signed with a secret. Unlike sessions, they donβt require server-side storage, making them scalable and tamper-evident.
4οΈβ£ What's the difference between Cookies and LocalStorage?
Answer:
- Cookies: Automatically sent with each HTTP request, smaller in size, can be
HttpOnly. - LocalStorage: Larger, persists longer, not sent with requests (manual access only).
5οΈβ£ What is CORS? Why is it important?
Answer:
CORS (Cross-Origin Resource Sharing) is a browser mechanism that restricts requests from different origins. It protects against unwanted cross-site access.
6οΈβ£ What is CSRF and how do you prevent it?
Answer:
CSRF (Cross-Site Request Forgery) tricks a logged-in user into submitting unwanted actions.
Prevention: Use CSRF tokens,
SameSite cookies, and avoid storing sensitive data in localStorage.7οΈβ£ What is XSS and how do you prevent it?
Answer:
XSS (Cross-Site Scripting) injects malicious scripts into web pages.
Prevention: Escape user input, use Content Security Policy (CSP), and sanitize HTML.
8οΈβ£ What is HTTPS and why is it critical?
Answer:
HTTPS encrypts data using SSL/TLS. It ensures data privacy, integrity, and trust between client and server.
9οΈβ£ How do you implement password security in web apps?
Answer:
- Store hashed passwords using bcrypt or Argon2
- Use salting
- Enforce strong password rules
- Implement rate-limiting on login attempts
π What is OAuth?
Answer:
OAuth is an authorization protocol that allows users to grant access to third-party apps without sharing credentials (e.g., login with Google/Facebook).
π¬ Tap β€οΈ if you found this useful!
β€1
β
API & Web Services β Web Development Interview Q&A ππ¬
1οΈβ£ What is an API?
Answer:
API (Application Programming Interface) allows communication between two software systems. It defines how requests and responses should be formatted.
2οΈβ£ REST vs SOAP β What's the difference?
Answer:
- REST: Lightweight, uses HTTP, supports JSON/XML
- SOAP: Protocol-based, strict standards, uses XML
REST is more common for modern web services.
3οΈβ£ What is RESTful API?
Answer:
An API that follows REST principles:
- Uses HTTP methods (GET, POST, PUT, DELETE)
- Stateless
- Has structured endpoints
- Supports caching
4οΈβ£ What are HTTP status codes?
Answer:
Codes returned in response:
- 200: OK
- 201: Created
- 400: Bad Request
- 401: Unauthorized
- 403: Forbidden
- 404: Not Found
- 500: Server Error
5οΈβ£ What is GraphQL?
Answer:
A query language for APIs by Facebook.
- Client defines the structure of the response
- Single endpoint
- Reduces over-fetching and under-fetching of data
6οΈβ£ What is CORS?
Answer:
Cross-Origin Resource Sharing β A security feature in browsers that blocks requests from other origins unless explicitly allowed by the server.
7οΈβ£ What is rate limiting?
Answer:
Limits the number of API requests a user/client can make within a time frame to prevent abuse.
8οΈβ£ What is an API key and how is it used?
Answer:
An API key is a token used to authenticate and authorize access to APIs. Itβs passed in headers or query strings.
9οΈβ£ Difference between PUT and PATCH?
Answer:
- PUT: Replaces the entire resource
- PATCH: Updates only specified fields
π What is a webhook?
Answer:
A way for servers to send data automatically to other services (e.g., when an event happens). Itβs push-based, unlike APIs which are pull-based.
π¬ Tap β€οΈ if you found this useful!
1οΈβ£ What is an API?
Answer:
API (Application Programming Interface) allows communication between two software systems. It defines how requests and responses should be formatted.
2οΈβ£ REST vs SOAP β What's the difference?
Answer:
- REST: Lightweight, uses HTTP, supports JSON/XML
- SOAP: Protocol-based, strict standards, uses XML
REST is more common for modern web services.
3οΈβ£ What is RESTful API?
Answer:
An API that follows REST principles:
- Uses HTTP methods (GET, POST, PUT, DELETE)
- Stateless
- Has structured endpoints
- Supports caching
4οΈβ£ What are HTTP status codes?
Answer:
Codes returned in response:
- 200: OK
- 201: Created
- 400: Bad Request
- 401: Unauthorized
- 403: Forbidden
- 404: Not Found
- 500: Server Error
5οΈβ£ What is GraphQL?
Answer:
A query language for APIs by Facebook.
- Client defines the structure of the response
- Single endpoint
- Reduces over-fetching and under-fetching of data
6οΈβ£ What is CORS?
Answer:
Cross-Origin Resource Sharing β A security feature in browsers that blocks requests from other origins unless explicitly allowed by the server.
7οΈβ£ What is rate limiting?
Answer:
Limits the number of API requests a user/client can make within a time frame to prevent abuse.
8οΈβ£ What is an API key and how is it used?
Answer:
An API key is a token used to authenticate and authorize access to APIs. Itβs passed in headers or query strings.
9οΈβ£ Difference between PUT and PATCH?
Answer:
- PUT: Replaces the entire resource
- PATCH: Updates only specified fields
π What is a webhook?
Answer:
A way for servers to send data automatically to other services (e.g., when an event happens). Itβs push-based, unlike APIs which are pull-based.
π¬ Tap β€οΈ if you found this useful!
β€4
β
Git & GitHub Interview Questions & Answers π§βπ»π
1οΈβ£ What is Git?
A: Git is a distributed version control system to track changes in source code during development.
2οΈβ£ What is GitHub?
A: GitHub is a cloud-based platform that hosts Git repositories and supports collaboration, issue tracking, and CI/CD.
3οΈβ£ Git vs GitHub
- Git: Version control tool (local)
- GitHub: Hosting service for Git repositories (cloud-based)
4οΈβ£ What is a Repository (Repo)?
A: A storage space where your projectβs files and history are saved.
5οΈβ£ Common Git Commands:
-
-
-
-
-
-
-
-
6οΈβ£ What is a Commit?
A: A snapshot of your changes. Each commit has a unique ID (hash) and message.
7οΈβ£ What is a Branch?
A: A separate line of development. The default branch is usually
8οΈβ£ What is Merging?
A: Combining changes from one branch into another.
9οΈβ£ What is a Pull Request (PR)?
A: A GitHub feature to propose changes, request reviews, and merge code into the main branch.
π What is Forking?
A: Creating a personal copy of someone elseβs repo to make changes independently.
1οΈβ£1οΈβ£ What is .gitignore?
A: A file that tells Git which files/folders to ignore (e.g., logs, temp files, env variables).
1οΈβ£2οΈβ£ What is Staging Area?
A: A space where changes are held before committing.
1οΈβ£3οΈβ£ Difference between Merge and Rebase
- Merge: Keeps all history, creates a merge commit
- Rebase: Rewrites history, makes it linear
1οΈβ£4οΈβ£ What is Git Workflow?
A: A set of rules like Git Flow, GitHub Flow, etc., for how teams manage branches and releases.
1οΈβ£5οΈβ£ How to Resolve Merge Conflicts?
A: Manually edit the conflicted files, mark resolved, then commit the changes.
π¬ Tap β€οΈ if you found this useful!
1οΈβ£ What is Git?
A: Git is a distributed version control system to track changes in source code during development.
2οΈβ£ What is GitHub?
A: GitHub is a cloud-based platform that hosts Git repositories and supports collaboration, issue tracking, and CI/CD.
3οΈβ£ Git vs GitHub
- Git: Version control tool (local)
- GitHub: Hosting service for Git repositories (cloud-based)
4οΈβ£ What is a Repository (Repo)?
A: A storage space where your projectβs files and history are saved.
5οΈβ£ Common Git Commands:
-
git init β Initialize a repo -
git clone β Copy a repo -
git add β Stage changes -
git commit β Save changes -
git push β Upload to remote -
git pull β Fetch and merge from remote -
git status β Check current state -
git log β View commit history 6οΈβ£ What is a Commit?
A: A snapshot of your changes. Each commit has a unique ID (hash) and message.
7οΈβ£ What is a Branch?
A: A separate line of development. The default branch is usually
main or master.8οΈβ£ What is Merging?
A: Combining changes from one branch into another.
9οΈβ£ What is a Pull Request (PR)?
A: A GitHub feature to propose changes, request reviews, and merge code into the main branch.
π What is Forking?
A: Creating a personal copy of someone elseβs repo to make changes independently.
1οΈβ£1οΈβ£ What is .gitignore?
A: A file that tells Git which files/folders to ignore (e.g., logs, temp files, env variables).
1οΈβ£2οΈβ£ What is Staging Area?
A: A space where changes are held before committing.
1οΈβ£3οΈβ£ Difference between Merge and Rebase
- Merge: Keeps all history, creates a merge commit
- Rebase: Rewrites history, makes it linear
1οΈβ£4οΈβ£ What is Git Workflow?
A: A set of rules like Git Flow, GitHub Flow, etc., for how teams manage branches and releases.
1οΈβ£5οΈβ£ How to Resolve Merge Conflicts?
A: Manually edit the conflicted files, mark resolved, then commit the changes.
π¬ Tap β€οΈ if you found this useful!
β€2
Dear friends π,
I want 2026 to be a year of bonding, connections, and real conversations π€
For years, we have shared courses, resources, news, and knowledge. But I want to talk with you, ask questions, give answers, and learn together.
With over 10 years in data science, software engineering, and AI π€, I have built and shipped real world systems that generated millions of dollars. I have made mistakes, learned valuable lessons, and I am always happy to share my experience openly.
β Feel free to ask me anything
Career, learning paths, real projects, tech decisions, or doubts.
This is why I am reminding you that each channel has its own discussion group.
You can open it via
or via the links below π
π Channels and their discussion groups
β’ Free courses by Big Data Specialist
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π¬ Join the conversations, ask questions, share your journey.
Looking forward to connecting with you all π
I will share this message across all our channels so everyone can see it. Hope you do not mind π
See you in the discussions π
I want 2026 to be a year of bonding, connections, and real conversations π€
For years, we have shared courses, resources, news, and knowledge. But I want to talk with you, ask questions, give answers, and learn together.
With over 10 years in data science, software engineering, and AI π€, I have built and shipped real world systems that generated millions of dollars. I have made mistakes, learned valuable lessons, and I am always happy to share my experience openly.
β Feel free to ask me anything
Career, learning paths, real projects, tech decisions, or doubts.
This is why I am reminding you that each channel has its own discussion group.
You can open it via
channel name β Discuss button
or via the links below π
π Channels and their discussion groups
β’ Free courses by Big Data Specialist
β linked discussion group
β’ Data Science / ML / AI
β linked discussion group
β’ GitHub Repositories
β linked discussion group
β’ Coding Interview Preparation
β linked discussion group
β’ Data Visualization
β linked discussion group
β’ Python Learning
β linked discussion group
β’ Tech News
β linked discussion group
β’ Logic Quest
β linked discussion group
β’ Data Science Research Papers
β linked discussion group
β’ Web Development
β linked discussion group
β’ AI Revolution
β linked discussion group
β’ Talks with ChatGPT
β linked discussion group
β’ Programming Memes
β linked discussion group
β’ Code Comics
β linked discussion group
π¬ Join the conversations, ask questions, share your journey.
Looking forward to connecting with you all π
I will share this message across all our channels so everyone can see it. Hope you do not mind π
See you in the discussions π
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Programming, Data and AI learning
Free courses, roadmaps and study materials.
Python, data science, ML, big data, AI, web, system design.
Join π https://rebrand.ly/bigdatachannels
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Free courses, roadmaps and study materials.
Python, data science, ML, big data, AI, web, system design.
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Contact: @mldatascientist
β€2π1
β
Git & GitHub Interview Questions & Answers (Part 2) π§ π»
1οΈβ£6οΈβ£ What is a Tag in Git?
A: A tag marks a specific point in history, often used for releases (e.g.,
1οΈβ£7οΈβ£ Difference between Soft, Mixed, and Hard Reset?
-
-
-
1οΈβ£8οΈβ£ What is Git Revert?
A: Reverts a commit by creating a new one that undoes changes, keeping history intact.
1οΈβ£9οΈβ£ What is Cherry Pick?
A: Apply a specific commit from one branch to another without merging the whole branch.
2οΈβ£0οΈβ£ What is Git Stash?
A: Temporarily saves uncommitted changes so you can switch branches safely.
2οΈβ£1οΈβ£ What is HEAD in Git?
A: A pointer to the current branch reference or latest commit in your working directory.
2οΈβ£2οΈβ£ What is the difference between
- origin: Default remote repo you cloned from
- upstream: Original repo you forked from (used in collaboration)
2οΈβ£3οΈβ£ What is Fast-forward Merge?
A: When no divergence, Git just moves the branch pointer forward β no new commit needed.
2οΈβ£4οΈβ£ Git Fetch vs Git Pull
- Fetch: Downloads changes without merging
- Pull: Fetch + Merge in one step
2οΈβ£5οΈβ£ How to Undo Last Commit?
π¬ Tap β€οΈ for more!
1οΈβ£6οΈβ£ What is a Tag in Git?
A: A tag marks a specific point in history, often used for releases (e.g.,
v1.0).1οΈβ£7οΈβ£ Difference between Soft, Mixed, and Hard Reset?
-
git reset --soft β Moves HEAD, keeps changes staged -
git reset --mixed (default) β Moves HEAD, unstages changes -
git reset --hard β Removes all changes1οΈβ£8οΈβ£ What is Git Revert?
A: Reverts a commit by creating a new one that undoes changes, keeping history intact.
1οΈβ£9οΈβ£ What is Cherry Pick?
A: Apply a specific commit from one branch to another without merging the whole branch.
2οΈβ£0οΈβ£ What is Git Stash?
A: Temporarily saves uncommitted changes so you can switch branches safely.
2οΈβ£1οΈβ£ What is HEAD in Git?
A: A pointer to the current branch reference or latest commit in your working directory.
2οΈβ£2οΈβ£ What is the difference between
origin and upstream? - origin: Default remote repo you cloned from
- upstream: Original repo you forked from (used in collaboration)
2οΈβ£3οΈβ£ What is Fast-forward Merge?
A: When no divergence, Git just moves the branch pointer forward β no new commit needed.
2οΈβ£4οΈβ£ Git Fetch vs Git Pull
- Fetch: Downloads changes without merging
- Pull: Fetch + Merge in one step
2οΈβ£5οΈβ£ How to Undo Last Commit?
git reset --soft HEAD~1 # Keeps changes staged
git reset --hard HEAD~1 # Discards changes completely
π¬ Tap β€οΈ for more!
β€6
β
CI/CD Pipeline Interview Questions & Answers βοΈπ
1οΈβ£ What is CI/CD?
A: CI/CD stands for Continuous Integration and Continuous Deployment/Delivery β practices that automate code integration, testing, and deployment.
2οΈβ£ What is Continuous Integration (CI)?
A: Developers frequently merge code into a shared repo. Each merge triggers automated builds & tests to detect issues early.
3οΈβ£ What is Continuous Deployment/Delivery (CD)?
- Delivery: Code is automatically prepared for release but needs manual approval.
- Deployment: Code is automatically pushed to production after passing tests.
4οΈβ£ Key Stages of a CI/CD Pipeline:
1. Code
2. Build
3. Test
4. Release
5. Deploy
6. Monitor
5οΈβ£ What tools are used in CI/CD?
- CI: Jenkins, GitHub Actions, CircleCI, GitLab CI
- CD: ArgoCD, Spinnaker, AWS CodeDeploy
6οΈβ£ What is a Build Pipeline?
A: A sequence of automated steps to compile, test, and prepare code for deployment.
7οΈβ£ What is a Webhook?
A: A trigger that starts the pipeline when new code is pushed to the repository.
8οΈβ£ What are Artifacts?
A: Output files generated after a build, like JARs, Docker images, etc., stored for deployment.
9οΈβ£ What is Rollback?
A: Reverting to the previous stable version if a deployment fails.
π Why is CI/CD important?
A: It increases code quality, reduces bugs, speeds up delivery, and ensures smoother collaboration.
π¬ Tap β€οΈ for more!
1οΈβ£ What is CI/CD?
A: CI/CD stands for Continuous Integration and Continuous Deployment/Delivery β practices that automate code integration, testing, and deployment.
2οΈβ£ What is Continuous Integration (CI)?
A: Developers frequently merge code into a shared repo. Each merge triggers automated builds & tests to detect issues early.
3οΈβ£ What is Continuous Deployment/Delivery (CD)?
- Delivery: Code is automatically prepared for release but needs manual approval.
- Deployment: Code is automatically pushed to production after passing tests.
4οΈβ£ Key Stages of a CI/CD Pipeline:
1. Code
2. Build
3. Test
4. Release
5. Deploy
6. Monitor
5οΈβ£ What tools are used in CI/CD?
- CI: Jenkins, GitHub Actions, CircleCI, GitLab CI
- CD: ArgoCD, Spinnaker, AWS CodeDeploy
6οΈβ£ What is a Build Pipeline?
A: A sequence of automated steps to compile, test, and prepare code for deployment.
7οΈβ£ What is a Webhook?
A: A trigger that starts the pipeline when new code is pushed to the repository.
8οΈβ£ What are Artifacts?
A: Output files generated after a build, like JARs, Docker images, etc., stored for deployment.
9οΈβ£ What is Rollback?
A: Reverting to the previous stable version if a deployment fails.
π Why is CI/CD important?
A: It increases code quality, reduces bugs, speeds up delivery, and ensures smoother collaboration.
π¬ Tap β€οΈ for more!
β€3
β
Docker Interview Questions & Answers π³π§
1οΈβ£ What is Docker?
A: Docker is an open-source platform that uses containerization to package, distribute, and run applications in isolated environments called containers.
2οΈβ£ What is a Container?
A: A lightweight, standalone executable package including code, runtime, libraries, and settingsβruns consistently across any system.
3οΈβ£ Docker vs Virtual Machines (VMs)
- Docker: Shares host OS kernel, fast & efficient (MBs)
- VMs: Full OS per instance, heavier (GBs), slower startup
4οΈβ£ What is a Docker Image?
A: A read-only template (like a snapshot) used to create containers; built from a Dockerfile with layers of instructions.
5οΈβ£ Common Docker Commands:
-
-
-
-
-
-
-
6οΈβ£ What is a Dockerfile?
A: A text file with instructions to automate building Docker images (e.g., FROM, RUN, COPY, CMD).
7οΈβ£ What is Docker Compose?
A: A tool for defining and running multi-container apps using YAML filesβmanages services, networks, volumes.
*8οΈβ£ What is Docker Hub?*
*A:* A public registry for storing and sharing Docker images, like GitHub for code.
9οΈβ£ What is Docker Swarm?
A: Docker's native clustering/orchestration tool for managing a swarm of Docker nodes and deploying services.
π What are Docker Volumes?
A: Persistent storage for containers; data survives container lifecycleβmount host directories or use named volumes.
1οΈβ£1οΈβ£ What is Docker Networking?
A: Connects containers and services; modes include bridge (default), host, overlay (for Swarm), none.
1οΈβ£2οΈβ£ How to Build a Docker Image?
A: Write a Dockerfile, run
1οΈβ£3οΈβ£ Difference between CMD and ENTRYPOINT?
- CMD: Default args for executable; can be overridden
- ENTRYPOINT: Sets container's executable; args append to it
1οΈβ£4οΈβ£ What is Container Orchestration?
A: Managing multiple containers at scale; tools like Kubernetes, Docker Swarm handle deployment, scaling, load balancing.
1οΈβ£5οΈβ£ How to Handle Docker Security?
A: Run as non-root, scan images (e.g., Trivy), use minimal base images, limit privileges, and keep software updated.
π¬ Tap β€οΈ if you found this useful!
1οΈβ£ What is Docker?
A: Docker is an open-source platform that uses containerization to package, distribute, and run applications in isolated environments called containers.
2οΈβ£ What is a Container?
A: A lightweight, standalone executable package including code, runtime, libraries, and settingsβruns consistently across any system.
3οΈβ£ Docker vs Virtual Machines (VMs)
- Docker: Shares host OS kernel, fast & efficient (MBs)
- VMs: Full OS per instance, heavier (GBs), slower startup
4οΈβ£ What is a Docker Image?
A: A read-only template (like a snapshot) used to create containers; built from a Dockerfile with layers of instructions.
5οΈβ£ Common Docker Commands:
-
docker run β Start a container from an image -
docker build β Create an image from Dockerfile -
docker ps β List running containers -
docker images β List available images -
docker stop β Stop a running container -
docker pull β Download an image from registry -
docker push β Upload image to registry 6οΈβ£ What is a Dockerfile?
A: A text file with instructions to automate building Docker images (e.g., FROM, RUN, COPY, CMD).
7οΈβ£ What is Docker Compose?
A: A tool for defining and running multi-container apps using YAML filesβmanages services, networks, volumes.
*8οΈβ£ What is Docker Hub?*
*A:* A public registry for storing and sharing Docker images, like GitHub for code.
9οΈβ£ What is Docker Swarm?
A: Docker's native clustering/orchestration tool for managing a swarm of Docker nodes and deploying services.
π What are Docker Volumes?
A: Persistent storage for containers; data survives container lifecycleβmount host directories or use named volumes.
1οΈβ£1οΈβ£ What is Docker Networking?
A: Connects containers and services; modes include bridge (default), host, overlay (for Swarm), none.
1οΈβ£2οΈβ£ How to Build a Docker Image?
A: Write a Dockerfile, run
docker build -t image-name. in the directoryβtags it for easy reference.1οΈβ£3οΈβ£ Difference between CMD and ENTRYPOINT?
- CMD: Default args for executable; can be overridden
- ENTRYPOINT: Sets container's executable; args append to it
1οΈβ£4οΈβ£ What is Container Orchestration?
A: Managing multiple containers at scale; tools like Kubernetes, Docker Swarm handle deployment, scaling, load balancing.
1οΈβ£5οΈβ£ How to Handle Docker Security?
A: Run as non-root, scan images (e.g., Trivy), use minimal base images, limit privileges, and keep software updated.
π¬ Tap β€οΈ if you found this useful!
β€3
β
Deployment Interview Questions & Answers βοΈπ
1οΈβ£ What is Deployment?
A: Deployment is the process of making a web application live and accessible to users by hosting it on a server or platform.
2οΈβ£ What is Netlify?
A: Netlify is a cloud platform to host static websites and frontend frameworks (like React, Vue). It supports continuous deployment from Git.
Features: Free SSL, custom domain, form handling, serverless functions, ideal for JAMstack apps.
3οΈβ£ What is Heroku?
A: Heroku is a platform-as-a-service (PaaS) that lets you deploy full-stack apps easily using Git.
Features: Supports Node.js, Python, Ruby, etc., free tier (apps sleep when inactive), one-click deployment & add-ons like PostgreSQL.
4οΈβ£ What is Vercel?
A: Vercel is a frontend deployment platform optimized for React and especially Next.js apps.
Features: Fast global CDN, serverless functions, instant preview links for each commit.
5οΈβ£ How does Continuous Deployment work?
A: You connect your GitHub repo to Netlify, Heroku, or Vercel. On every push, the app builds and deploys automatically.
6οΈβ£ How do you deploy on Netlify?
A: Push your code to GitHub β Connect repo to Netlify β Configure build settings β Click "Deploy".
7οΈβ£ How do you deploy on Heroku?
A: Install Heroku CLI β Run:
8οΈβ£ How do you deploy on Vercel?
A: Login to Vercel β Import Git repo β Set up framework and build command β Deploy.
9οΈβ£ Which platform is best for static sites?
A: Netlify or Vercel β both offer free tiers, CDN, and fast performance.
π How to handle environment variables in these platforms?
A:
- Netlify: Go to Site Settings β Environment
- Heroku: Use
- Vercel: Project β Settings β Environment Variables
π¬ Tap β€οΈ for more!
1οΈβ£ What is Deployment?
A: Deployment is the process of making a web application live and accessible to users by hosting it on a server or platform.
2οΈβ£ What is Netlify?
A: Netlify is a cloud platform to host static websites and frontend frameworks (like React, Vue). It supports continuous deployment from Git.
Features: Free SSL, custom domain, form handling, serverless functions, ideal for JAMstack apps.
3οΈβ£ What is Heroku?
A: Heroku is a platform-as-a-service (PaaS) that lets you deploy full-stack apps easily using Git.
Features: Supports Node.js, Python, Ruby, etc., free tier (apps sleep when inactive), one-click deployment & add-ons like PostgreSQL.
4οΈβ£ What is Vercel?
A: Vercel is a frontend deployment platform optimized for React and especially Next.js apps.
Features: Fast global CDN, serverless functions, instant preview links for each commit.
5οΈβ£ How does Continuous Deployment work?
A: You connect your GitHub repo to Netlify, Heroku, or Vercel. On every push, the app builds and deploys automatically.
6οΈβ£ How do you deploy on Netlify?
A: Push your code to GitHub β Connect repo to Netlify β Configure build settings β Click "Deploy".
7οΈβ£ How do you deploy on Heroku?
A: Install Heroku CLI β Run:
git push heroku main β App will be deployed on a Heroku domain.8οΈβ£ How do you deploy on Vercel?
A: Login to Vercel β Import Git repo β Set up framework and build command β Deploy.
9οΈβ£ Which platform is best for static sites?
A: Netlify or Vercel β both offer free tiers, CDN, and fast performance.
π How to handle environment variables in these platforms?
A:
- Netlify: Go to Site Settings β Environment
- Heroku: Use
heroku config:set VAR_NAME=value - Vercel: Project β Settings β Environment Variables
π¬ Tap β€οΈ for more!
β€5
Forwarded from Cool GitHub repositories
awesome-interview-questions
A massive collection of interview questions for software engineers, data scientists, QA testers, DevOps, and mobile developers. Categorized by role and technology.
Creator: DOP251
Stars βοΈ: 80,500
Forked by: 9,300
Github Repo:
https://github.com/DopplerHQ/awesome-interview-questions
#Interviews #Careers #Tech
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Join @github_repositories_bds for more cool repositories. This channel belongs to @bigdataspecialist group
A massive collection of interview questions for software engineers, data scientists, QA testers, DevOps, and mobile developers. Categorized by role and technology.
Creator: DOP251
Stars βοΈ: 80,500
Forked by: 9,300
Github Repo:
https://github.com/DopplerHQ/awesome-interview-questions
#Interviews #Careers #Tech
ββββββββββββββ
Join @github_repositories_bds for more cool repositories. This channel belongs to @bigdataspecialist group
GitHub
GitHub - DopplerHQ/awesome-interview-questions: :octocat: A curated awesome list of lists of interview questions. Feel free toβ¦
:octocat: A curated awesome list of lists of interview questions. Feel free to contribute! :mortar_board: - DopplerHQ/awesome-interview-questions
β€3
β
Top 50 DSA (Data Structures & Algorithms) Interview Questions πβοΈ
1. What is a Data Structure?
2. What are the different types of data structures?
3. What is the difference between Array and Linked List?
4. How does a Stack work?
5. What is a Queue? Difference between Queue and Deque?
6. What is a Priority Queue?
7. What is a Hash Table and how does it work?
8. What is the difference between HashMap and HashSet?
9. What are Trees? Explain Binary Tree.
10. What is a Binary Search Tree (BST)?
11. What is the difference between BFS and DFS?
12. What is a Heap?
13. What is a Trie?
14. What is a Graph?
15. Difference between Directed and Undirected Graph?
16. What is the time complexity of common operations in arrays and linked lists?
17. What is recursion?
18. What are base case and recursive case?
19. What is dynamic programming?
20. Difference between Memoization and Tabulation?
21. What is the Sliding Window technique?
22. Explain Two-Pointer technique.
23. What is the Binary Search algorithm?
24. What is the Merge Sort algorithm?
25. What is the Quick Sort algorithm?
26. Difference between Merge Sort and Quick Sort?
27. What is Insertion Sort and how does it work?
28. What is Selection Sort?
29. What is Bubble Sort and its drawbacks?
30. What is the time and space complexity of sorting algorithms?
31. What is Backtracking?
32. Explain the N-Queens Problem.
33. What is the Kadane's Algorithm?
34. What is Floydβs Cycle Detection Algorithm?
35. What is the Union-Find (Disjoint Set) algorithm?
36. What are topological sorting and its uses?
37. What is Dijkstra's Algorithm?
38. What is Bellman-Ford Algorithm?
39. What is Kruskalβs Algorithm?
40. What is Primβs Algorithm?
41. What is Longest Common Subsequence (LCS)?
42. What is Longest Increasing Subsequence (LIS)?
43. What is a Palindrome Substring problem?
44. What is the difference between greedy and dynamic programming?
45. What is Big-O notation?
46. What is the difference between time and space complexity?
47. How to find the time complexity of a recursive function?
48. What are amortized time complexities?
49. What is tail recursion?
50. How do you approach solving a coding problem in interviews?
π¬ Tap β€οΈ for the detailed answers!
1. What is a Data Structure?
2. What are the different types of data structures?
3. What is the difference between Array and Linked List?
4. How does a Stack work?
5. What is a Queue? Difference between Queue and Deque?
6. What is a Priority Queue?
7. What is a Hash Table and how does it work?
8. What is the difference between HashMap and HashSet?
9. What are Trees? Explain Binary Tree.
10. What is a Binary Search Tree (BST)?
11. What is the difference between BFS and DFS?
12. What is a Heap?
13. What is a Trie?
14. What is a Graph?
15. Difference between Directed and Undirected Graph?
16. What is the time complexity of common operations in arrays and linked lists?
17. What is recursion?
18. What are base case and recursive case?
19. What is dynamic programming?
20. Difference between Memoization and Tabulation?
21. What is the Sliding Window technique?
22. Explain Two-Pointer technique.
23. What is the Binary Search algorithm?
24. What is the Merge Sort algorithm?
25. What is the Quick Sort algorithm?
26. Difference between Merge Sort and Quick Sort?
27. What is Insertion Sort and how does it work?
28. What is Selection Sort?
29. What is Bubble Sort and its drawbacks?
30. What is the time and space complexity of sorting algorithms?
31. What is Backtracking?
32. Explain the N-Queens Problem.
33. What is the Kadane's Algorithm?
34. What is Floydβs Cycle Detection Algorithm?
35. What is the Union-Find (Disjoint Set) algorithm?
36. What are topological sorting and its uses?
37. What is Dijkstra's Algorithm?
38. What is Bellman-Ford Algorithm?
39. What is Kruskalβs Algorithm?
40. What is Primβs Algorithm?
41. What is Longest Common Subsequence (LCS)?
42. What is Longest Increasing Subsequence (LIS)?
43. What is a Palindrome Substring problem?
44. What is the difference between greedy and dynamic programming?
45. What is Big-O notation?
46. What is the difference between time and space complexity?
47. How to find the time complexity of a recursive function?
48. What are amortized time complexities?
49. What is tail recursion?
50. How do you approach solving a coding problem in interviews?
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