Daily Coding Challenges & Projects

Frontend Mini Project Challenge

CSS Animation Effects

Challenge :

Create a "typing text animation" effect using only CSS (no JavaScript allowed).

Requirements :

• Use @keyframes and steps()
• Simulate typing of a sentence like: "Welcome to CodeZone!"
• Include a blinking caret animation

Try it here : CSS Typing Effect on CodePen (Search “typing text css animation”)

Backend Challenge

Java / Kotlin Focus

Challenge :

Write a Kotlin function to convert a Roman numeral string (e.g., "MCMXCIV") to its integer value.

Bonus (Java version) : Implement the same logic using a Map<Character, Integer>.

Database Query Challenge

Problems on SQL - HR Database :

1. Write a SQL query to find employees who report to the same manager as 'David Austin'.
2. List all departments where the average salary is higher than the company-wide average.

Data Structures & Algorithms Challenge

• Easy:
• Problem: Given an array, find the first non-repeating element.
• Hint: Use a LinkedHashMap to store counts while preserving order.
• Medium:
• Problem: Implement a Least Recently Used (LRU) Cache in Java/Kotlin.
• Hint: Use a LinkedHashMap with access-order set to true.
• Hard:
• Problem: Given an array of integers, return the length of the longest consecutive elements sequence.
• Hint: Use a HashSet to check for sequence starts in O(n).

Bug of the Day

Java/Kotlin Focus

Language: Java

Buggy Code:

public class SumExample {
    public static void main(String[] args) {
        int total = add(5, 10);
        System.out.println("Total: " + total);
    }

    static int add(int a, int b) {
        return a + b
    }
}

Challenge :

• Identify and fix the syntax error(s).
• Bonus: Convert it into Kotlin and run it!

📋 Daily Micro-Project

Backend :

Challenge :

Create a simple Spring Boot REST API (Java/Kotlin) with one endpoint:

GET /hello → Response: {"message": "Hello from Spring Boot!"}

Requirements :

• Use annotations like @RestController and @GetMapping
• Should run without external DB

Trivia: 5 Fun Facts

1. Java was originally called Oak.
2. Kotlin is officially supported by Google for Android.
3. CSS was invented by Håkon Wium Lie in 1994.
4. Oracle acquired Sun Microsystems in 2010.
5. The name “Spring” was inspired by the idea of a new beginning after the “winter” of J2EE.

Tool of the Day (Updated)

Tool : Lottie by Airbnb

• Use JSON-based animations in your websites and mobile apps.

Resource Roundup:

• CSS Animation Cheat Sheet
• Spring Boot Quick Start Guide
• Free Java Tutorial by JetBrains Academy

Interview Question of the Day

Daily Interview Questions

Frontend : :
1. What is the difference between em and rem in CSS?
2. How does the CSS z-index property work with stacking contexts?
3. How do you trigger hardware-accelerated animations in CSS?
4. Explain the difference between position: absolute and position: fixed.

Backend :
1. What are checked vs unchecked exceptions in Java?
2. How do Java Streams work internally?
3. Explain the role of coroutines in Kotlin.
4. How does Java's HashMap handle collisions?

Database :
1. What is the difference between GROUP BY and PARTITION BY?
2. Explain normalization and its levels (1NF, 2NF, 3NF).
3. What is a correlated subquery? Provide an example.

Others :
1. What is the JVM and how does it work?
2. How does continuous integration (CI) improve software delivery?

Daily Quiz Challenge

Frontend : CSS Focus

1. What CSS property controls the speed of an animation?
• animation-duration
• transition-delay
• animation-speed
• timing-function
2. Which unit is relative to the root font size?
• px
• em
• rem
• %
3. What does @keyframes do in CSS?
• Create responsive layouts
• Define a gradient
• Define animation behavior
• Import other CSS files

Backend (Java/Kotlin) :

1. What is the default access modifier for a class in Java?
• public
• private
• protected
• package-private
2. What does val mean in Kotlin?
• A mutable variable
• A loop
• An immutable variable
• A Kotlin function
3. In Java, what does the static keyword signify?
• The method belongs to the class
• The method runs in parallel
• It’s not inheritable
• It's an abstract method

Database :

1. What SQL keyword is used to sort result sets?
• WHERE
• HAVING
• GROUP BY
• SELECT

Mixed Quiz :

1. Which of the following is used to schedule tasks in Linux?
• cron
• npm
• gradle
• gulp

Weekly Cross-Domain Activities ( Updated ) ( May 02 to May 08, 2025 )

API of the Day:

Challenge : Cat Facts API

Build a fun web app that displays random cat facts. Add a "New Fact" button to fetch and display a new fact with each click.

API: https://catfact.ninja/fact

Linux/DevOps Tip:

Automate Backups with cron

Use crontab -e to schedule a daily backup of a directory:

0 2 * * * tar -czf /backup/$(date +\%F).tar.gz /your/data/folder

This runs at 2:00 AM daily and compresses your target folder into a date-stamped .tar.gz archive.

Real-World Project of the Week ( Updated ) ( May 02 to May 08, 2025 )

Project of the Week:

Build a Markdown Blog Engine using Node.js + Express or Flask.

• Users should be able to create blog posts using Markdown files. Convert them to HTML for rendering.

Collaborative Project:

Contribute to Public APIs GitHub repo — help by submitting useful APIs or improving documentation for developers worldwide.

Case Study:

Study "Trello" clone functionality

Focus on drag-and-drop lists, card management, and task labels using React + Redux or Vue + Pinia.