Daily Coding Challenges & Projects

Frontend Mini Project Challenge

Category : React Hooks

Challenge :

Build a "Counter with Undo/Redo" feature using React Hooks.

• Use useState for the counter value.
• Use an array to store history and allow users to undo/redo changes.

Bonus : Disable Undo if there's no history, and disable Redo if there's nothing to redo.

Hint : useReducer can be an even cleaner approach.

Backend Challenge

Category : Node.js, Go

Problem :

Create a REST API endpoint in Node.js (Express) that:

• Accepts a GET request at /random-joke
• Fetches a random joke from an external API (https://official-joke-api.appspot.com/random_joke)
• Returns the joke JSON to the client.

Bonus : Implement caching for 30 seconds so repeated requests don’t call the external API every time.

Database Query Challenge

Problems on SQL - HR Database :

1. Find Employees With More Than 10 Years of Service
2. List Departments With More Than 5 Employees

Data Structures & Algorithms Challenge

• Easy:
• Problem :Reverse a string without using built-in reverse methods.
• Hint :Use a loop and build the reversed string character by character.
• Medium:
• Problem : Implement a queue using two stacks.
• Hint :Use one stack for enqueue operations, and another for dequeue operations.
• Hard:
• Problem :Find the length of the longest increasing subsequence in an array.
• Hint :Dynamic Programming – store LIS ending at each index and update.

Bug of the Day

Language : Node.js / JavaScript

Buggy Code:

let data = { name: "Alex" };
console.log(data.name.toUppercase());

Challenge : Find and fix the bug.

📋 Daily Micro-Project

Type : Frontend

Task :

Build a Responsive Navbar with a hamburger menu using HTML, CSS, and JavaScript.

• Hamburger icon should toggle menu visibility.
• Works on both desktop and mobile.

Trivia: 5 Fun Facts

1. JavaScript was created in 10 days by Brendan Eich in 1995.
2. Node.js is built on Chrome's V8 JavaScript engine.
3. React was originally created by a Facebook engineer.
4. The Go language was developed at Google in 2009.
5. CSS Grid was first widely supported in browsers in 2017.

Tool & Resource of the Day

Tool : React Query

Use : A powerful data-fetching library for React.

• Handles caching, re-fetching, and background updates automatically.
• Great for APIs and server state management.

Interview Question of the Day

Daily Interview Questions

Frontend :
1. What is the difference between useEffect and useLayoutEffect in React?
2. Explain how React's useState batching works.
3. How does React reconcile DOM changes?
4. What is the purpose of useRef in React?

Backend :
1. How does Node.js handle asynchronous code?
2. Explain the event loop in Node.js.
3. What is middleware in Express.js?
4. How is concurrency managed in Go?

Database :
1. Explain the difference between EXISTS and IN in SQL.
2. What is a composite index?
3. How do you implement pagination in SQL queries?

Others :
1. What is a load balancer and why is it used?
2. Explain the concept of serverless computing.

Daily Quiz Challenge

Frontend ( React / JS ) :

1. What will this print?

const [count, setCount] = React.useState(0);
setCount(count + 1);
setCount(count + 1);
console.log(count);

2. Which hook is best for fetching data in React?
3. What is JSX?

Backend ( Node.js, Go ) :

1. What is the purpose of package.json in Node.js?
2. Which Go keyword is used to start a goroutine?
3. What is the difference between blocking and non-blocking I/O?

Mixed :

1. Database :Which SQL statement is used to remove a table from a database?
2. Other :Which company originally created Kubernetes?

Weekly Cross-Domain Activities ( August 01 to August 07, 2025 )

API of the Day:

Build a crypto tracker using the CoinGecko API.

Display current prices and 24h change of selected coins.

Linux/DevOps Tip :

Top 10 htop features for server monitoring (process tree, CPU graph, filter by user, etc.)

Real-World Project of the Week ( August 01 to August 07, 2025 )

Project of the Week:

Build a Task Manager App with React + Node.js + MongoDB (MERN Stack)

Collaborative Project:

Create an Open Source GitHub repo for “Interview Prep Hub” – collect user-submitted questions and answers.

Case Study:

Explore how Notion manages blocks and rich content – replicate a basic block-based note editor with contenteditable elements.