Daily Coding Challenges & Projects

Frontend Mini Project Challenge

Theme: React Hooks & State Management

Challenge :

Build a React component for a live character counter.

Requirements :

• Use useState to track input text
• Display character count as the user types
• Change counter color if limit exceeds

Bonus : Use useEffect to trigger a warning after a threshold.

Backend Challenge

Language Focus : Node.js, Go

Challenge :

Node.js + Express API : Create an endpoint that receives a POST request with user details and stores them in memory.

Bonus: Add validation using express-validator and return appropriate HTTP status codes.

Database Query Challenge

Problems on SQL - HR Database :

1. Write a SQL query to find employees who haven't changed departments in the last 2 years.
2. Write a query to list departments with the average salary above the overall company average.

Data Structures & Algorithms Challenge

• Easy:
• Problem : Find the index of the first non-repeating character in a string.
• Hint : Use a hashmap to count characters.
• Medium:
• Problem : Implement a min stack with O(1) getMin().
• Hint : Use an auxiliary stack to track mins.
• Hard:
• Problem : Solve the Longest Increasing Subsequence problem using binary search.
• Hint : Maintain a tail array and use bisect (or similar).

Bug of the Day

Language Focus :

Language : Node.js (JavaScript)

Buggy Code:

// What's wrong?
const users = ['Alice', 'Bob', 'Charlie'];
users.forEach(async user => {
  const result = await sendWelcomeEmail(user);
  console.log(result);
});

Fix the bug. :

Hint : Does forEach play nicely with async/await?

📋 Daily Micro-Project

Frontend Focus :

Project :

Build a responsive toggle switch (light/dark mode) in React using Tailwind CSS.

Bonus : Store theme preference in localStorage.

Trivia: 5 Fun Facts

1. React was initially developed at Facebook in 2011.
2. Go (Golang) was created at Google by Robert Griesemer, Rob Pike, and Ken Thompson.
3. JavaScript was developed in 10 days by Brendan Eich.
4. The term "callback hell" originates from nested asynchronous functions in JS.
5. Tailwind CSS was created by Adam Wathan in 2017.

Tool & Resource of the Day

Tool : Insomnia

API testing tool similar to Postman but lightweight and developer-friendly.

https://insomnia.rest

Resource Roundup :

• React Docs on useState and useEffect

Interview Question of the Day

Daily Interview Questions

Frontend :
1. What are React hooks? Name a few.
2. What is the use of useEffect in React?
3. How does React handle form input elements?
4. Explain the concept of lifting state up in React.

Backend :
1. How does Node.js handle concurrency?
2. What is the event loop in Node.js?
3. How do goroutines differ from threads in Go?
4. What are closures in JavaScript and why are they useful in backend code?

Database ( SQL ) :
1. What is a foreign key constraint?
2. How can you prevent duplicate entries in a table?
3. Explain normalization and its types.

Others :
1. What is the purpose of a package manager like npm or yarn?
2. What is CI/CD in modern software development?

Daily Quiz Challenge

Frontend Quiz :

1. Which hook is used to manage side effects in React?
• useState
• useEffect
• useReducer
• useRef
2. In React, useState returns:
• A function
• A value and function
• A reducer
• A prop
3. Tailwind CSS is:
• A JS library
• A CSS preprocessor
• A utility-first CSS framework
• A CSS-in-JS tool

Backend Quiz :

1. Which function is used to start a server in Express?
• listen()
• run()
• connect()
• start()
2. In Go, go func() is used to:
• Call API
• Declare main
• Launch goroutine
• Print value
3. What's the purpose of require() in Node.js?
• Import modules
• Export data
• Handle requests
• Connect DB

Others :

1. Database : Which keyword groups rows with the same values?
• WHERE
• GROUP BY
• ORDER BY
• LIMIT
2. General : What does CI stand for?
• Continuous Input
• Constant Integration
• Continuous Integration
• Config Integration

Weekly Cross-Domain Activities ( June 20 to June 26, 2025 )

API of the Day:

Task : Integrate the News API to fetch top headlines based on user-selected categories.

Bonus : Add search and filter by country or keyword.

Linux/DevOps Tip :

Title : Monitor Server Resources

Commands :

• top – Live process monitoring
• df -h – Disk space usage
• free -m – Memory usage
• uptime – Server load
• lsof – Open files

Real-World Project of the Week ( June 20 to June 26, 2025 )

Project of the Week:

Build a Resume Builder Web App

• Tech Stack: HTML, CSS, JavaScript (React optional)
• Features: Section-wise input (Education, Experience, Skills), Live Preview, Download as PDF

Collaborative Project:

Idea : Open-source a Daily Code Challenge Tracker

• Use GitHub Projects or issues to track challenges.
• Allow contributors to submit PRs for daily code solutions.

Case Study:

How Netflix Handles Streaming at Scale

• Topics: CDN, Microservices, Chaos Engineering
• Activity: Recreate a mini Netflix UI with static video thumbnails and categories using React or Vue.