Daily Coding Challenges & Projects

Frontend Mini Project Challenge

JavaScript Logical Puzzle:

Challenge:

• Write a function to flatten a nested array without using recursion.

Example:

flatten([1, [2, [3, 4]], 5]); // Output: [1, 2, 3, 4, 5]

Backend Challenge

Language Focus: C, C++, C#

Challenge:

• Reverse a singly linked list.

Database Query Challenge

Problems on SQL - HR Database :

1. Find employees who joined in the last 3 months.
2. Identify employees without a salary increase in the last 2 years.

Data Structures & Algorithms Challenge

• Easy:
• Problem: Check if a string is a palindrome.
• Hint: Compare characters from both ends moving towards the center.
• Medium:
• Problem: Implement a queue using two stacks
• Hint: Use one stack for enqueue operations and another for dequeue operations.
• Hard:
• Problem: Find the longest palindromic substring in a given string.
• Hint: Expand around potential centers to find palindromes.

Bug of the Day

Language Focus: C

Buggy Code:

int main() {
    int a = 5;
    if (a = 10) {
        printf("a is 10\n");
    }
    return 0;
}​:contentReference[oaicite:44]{index=44}

Challenge: Identify and correct the error.

📋 Daily Micro-Project

Task:

Create a CSS-only loading spinner.

• Hint:
• Use @keyframes and transform properties to animate a circular element.

Trivia: 5 Fun Facts

1. Who developed the C programming language?
2. What does "CSS" stand for?
3. Which company created the Java programming language?
4. What is the purpose of the git version control system?
5. Who is known as the father of the World Wide Web?

Tool of the Day

Tool: Cypress

Resource Roundup:

Interview Question of the Day

Daily Interview Questions

Frontend :
1. What is the difference between null and undefined in JavaScript?
2. Explain how the event delegation pattern works in JavaScript.
3. How does the Virtual DOM work in React, and why is it useful?
4. What are the key differences between Vue.js computed properties and watchers?

Backend :
1. Explain the difference between synchronous and asynchronous programming in Node.js.
2. What is the difference between a thread and a process?
3. How does memory management work in Python?
4. Explain how a RESTful API differs from GraphQL.

Database :
1. What is the difference between INNER JOIN and LEFT JOIN in SQL?
2. How does indexing improve query performance in databases?
3. What is the difference between NoSQL and SQL databases?

Others :
1. What are system calls in an operating system? Provide an example.
2. What is containerization, and how does Docker help in deployment?

Daily Quiz Challenge

Frontend :

1. What is the output of console.log(typeof null);?
2. Which HTML tag is used to define

Weekly Cross-Domain Activities ( April 18 to 24, 2025 )

API of the Day:

Build a currency converter using the ExchangeRate API

• Fetch live exchange rates
• User selects currency pair and amount
• Displays converted amount instantly

Linux/DevOps Tip:

10 Commands to Monitor Server Health:

Real-World Project of the Week ( April 18 to 24, 2025 )

Project of the Week:

Build a Task Manager App with login, add/edit/delete tasks, and due date reminders

• Tech Stack Options:
• React + Node.js + PostgreSQL

Collaborative Project:

Open-source GitHub Project: Habit Tracker App** ← let users add habits, track streaks, share progress. Invite community collaboration!

Case Study:

How Trello Works Under the Hood

• Real-time updates using WebSockets
• Kanban board layout
• Offline support via IndexedDB