Daily Coding Challenges & Projects

Frontend Mini Project Challenge (Updated)

Focus: CSS Animation Effects

Challenge :

Create a glowing button using only CSS that pulses when hovered.

Requirements :

• Use @keyframes to animate a glow.
• Button should have a smooth infinite pulse effect.

Click Me
 
.glow-button {
  padding: 12px 24px;
  border: none;
  background: #0f0;
  color: #000;
  font-size: 18px;
  border-radius: 8px;
  box-shadow: 0 0 10px #0f0;
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0% {
    box-shadow: 0 0 10px #0f0;
  }
  50% {
    box-shadow: 0 0 20px #0f0, 0 0 30px #0f0;
  }
  100% {
    box-shadow: 0 0 10px #0f0;
  }
}

Try it Online: JSFiddle

Backend Challenge

Language Focus: Java, Kotlin

Java Challenge :

Task : Create a RESTful API endpoint using Spring Boot that returns a list of products as JSON.

Kotlin Challenge :

Task : Write a Kotlin function that returns the first non-repeating character from a string.

Database Query Challenge

Problems on SQL - HR Database :

1. Write a SQL query to list employees who joined in the last 3 months.
2. Write a query to find employees whose salary is above the department average salary.

Data Structures & Algorithms Challenge

• Easy:
• Problem : Given a string, reverse it without using built-in reverse functions.
• Hint : Use a loop and swap characters.
• Medium:
• Problem : Implement a function that checks if a given linked list contains a cycle.
• Hint : Use Floyd’s cycle-finding algorithm (tortoise and hare).
• Hard:
• Problem : Given n tasks with a cooling interval k, schedule tasks such that the same task cannot be run again until after k intervals. Return the minimum time required to complete all tasks.
• Hint : Use a priority queue and greedy approach.

Bug of the Day

Language Focus: Java, Kotlin

Java Bug :

Buggy Code:

String str = null;
if (str.equals("hello")) {
    System.out.println("It's hello!");
}

Challenge : What's wrong with the code? Fix it.

Kotlin Bug :

Buggy Code:

val numbers = listOf(1, 2, 3, 4)
println(numbers[4])

Challenge : What will happen? Fix the bug.

📋 Daily Micro-Project

Backend Task :

Micro Project :

Build a small backend in Kotlin (Ktor) or Java (Spring Boot) to serve a random quote from a list.

• One endpoint: /random-quote
• Response: JSON { "quote": "..." }

Trivia: 5 Fun Facts

1. The first programming language was Fortran, developed in the 1950s.
2. Kotlin was officially supported for Android in 2017.
3. The word "bug" in computing predates actual computer bugs—it was used as early as 1878.
4. Java was originally designed for interactive television.
5. The Linux mascot Tux is a penguin because Linus Torvalds liked penguins.

Tool & Resource of the Day

Tool : CSS Doodle

Generate art and interactive visual patterns using CSS and custom elements.

Website :https://css-doodle.com

Resource :CSS Doodle Playground

Interview Question of the Day

Daily Interview Questions

Frontend :
1. What is the z-index in CSS and how does it work?
2. How do CSS transitions differ from CSS animations?
3. What are the differences between position: relative, absolute, and fixed?
4. How does Vue’s two-way data binding work?

Backend :
1. What is the difference between an interface and an abstract class in Java?
2. What is a coroutine in Kotlin?
3. How does garbage collection work in Java?
4. Explain exception handling in Kotlin.

Database :
1. What is a composite primary key?
2. How does the GROUP BY clause work in SQL?
3. What are the ACID properties of transactions?

Others :
1. What is a virtual machine (VM)?
2. What is an SDK, and how is it different from an API?

Daily Quiz Challenge

Frontend ( CSS Focus ) :

1. Which CSS property is used for animations?
• transition
• animation
• motion
• effect
2. What is the default position value for an element?
• absolute
• fixed
• relative
• static
3. What will this do?

div {
  animation: slide 1s infinite;
}

• Nothing
• Slide the div once
• Slide continuously
• Crash the browser

Backend ( Java/Kotlin ) :

1. What is the keyword used to inherit a class in Java?
• inherit
• extends
• super
• implements
2. What is a lambda in Kotlin?
• A class
• A variable
• An anonymous function
• A package
3. Java is:
• Interpreted only
• Compiled only
• Compiled and interpreted
• None of the above

Database ( SQL ) :

1. Which clause filters rows before aggregation?
• WHERE
• HAVING
• ORDER BY
• LIMIT

Others :

1. Which of these is a system call?
• printf()
• malloc()
• read()
• sort()

Mixed Quiz :

1. JavaScript and Java are:
• Same
• Interchangeable
• Totally different
• Both back-end languages

Weekly Cross-Domain Activities (Updated) ( May 16 to May 22, 2025 )

API of the Day:

Use the NASA Astronomy Picture of the Day (APOD) API

Challenge :

Build a mini web app that fetches and displays the daily astronomy picture from NASA's APOD API with its title and description.

• Challenge Add-on: Add a date picker to view past pictures.
• NASA APOD API Documentation

Linux/DevOps Tip :

Monitor Disk Usage with du and ncdu

Commands :

• Use du -sh * to get a summary of disk usage by folder.
• Use ncdu (if installed) for a more interactive and visual exploration of what's eating up space in your directories.

Real-World Project of the Week (Updated) ( May 16 to May 22, 2025 )

Project of the Week:

Build a Blog Platform with Markdown Support

• Use a backend like Node.js, Flask, or Django.
• Use a markdown parser (like marked in JS or markdown in Python) to render posts.
• Add support for categories, tags, and featured images.

Bonus : Allow login functionality to create/edit/delete posts.

Collaborative Project:

Create a “Dev Tools Hub” Web App.

• A multi-tool app offering features like:
• JSON formatter
• UUID generator
• Base64 encoder/decoder
• Regex tester
• Organize collaboration via GitHub and assign different tools to team members.

Case Study:

How Trello Works — Kanban Task Boards.

• Study how Trello organizes cards, lists, and boards.
• Build a mini Kanban board with drag-and-drop functionality using Sortable.js or native drag-and-drop API.
• Focus on data modeling and client-server sync logic.