Daily Coding Challenges & Projects

Frontend Mini Project Challenge

Create a Color Palette Generator:

Challenge:

• Build a mini app using JavaScript + CSS + HTML (or React if preferred) that lets users generate and copy hex codes of random color palettes.

• Features:
• Click "Generate" to get 5 new random colors.
• Click any color to copy its hex code.
• Option to lock specific colors before regenerating.

Bonus: Allow light/dark mode toggle.

Try it online: Use platforms like CodeSandbox or JSFiddle

Backend Challenge

Scala, R, Swift, TypeScript

Scala Challenge:

Problem:

Write a Scala program that implements a mini in-memory key-value store with put, get, and delete methods using mutable Map.

R Challenge

Problem:

Read a CSV file containing employee salary data and calculate:

• Average salary by department
• Number of employees earning above the average

Swift (Vapor)

Problem:

Create a simple POST API to accept contact form submissions and store in memory.

TypeScript (Node.js + Express)

Problem:

Build a REST API with one endpoint: GET /summary?text=...

Use a dummy logic to return first 20 characters of the input text as "summary".

Database Query Challenge

Problems on SQL - HR Database :

1. Employees whose salary is below the average salary of their department.
2. Managers who are managing more than 5 employees.

Data Structures & Algorithms Challenge

• Easy:
• Problem: Given a string, determine if it's a palindrome ignoring non-alphanumeric characters.
• Hint: Normalize the string using regex and compare it with its reverse.
• Medium:
• Problem: Implement an LRU (Least Recently Used) Cache using a doubly linked list and a hashmap.
• Hint: Use a fixed-capacity and eviction strategy on insertion.
• Hard:
• Problem: Serialize and Deserialize a Binary Tree.
• Hint: Use preorder traversal for serialization and recursion for deserialization.

Bug of the Day

Scala, R, Swift, TypeScript

Bug (TypeScript):

Code:

function greet(name: string) {
  return "Hello, " + name.toUpper();
}
console.log(greet("Sam"));
});

Challenge: Fix the bug — what's wrong?

Bug (Swift):

Code:

let ages = [21, 25, 30]
print(ages[3])

Challenge: Find and fix the issue — what’s the correct way to avoid runtime crashes?

📋 Daily Micro-Project

Backend

Challenge: Build a simple file upload API

Create an endpoint using TypeScript + Express that:

• Accepts file uploads (multipart/form-data)
• Saves files to local folder
• Returns original file name and size

Trivia: 5 Fun Facts

1. Git was created by Linus Torvalds in just 10 days.
2. The first high-level language was Fortran, developed in 1957.
3. Java was initially called “Oak.”
4. Python is named after Monty Python, not the snake.
5. The first computer bug was an actual moth found in a relay.

Tool of the Day

Tool : Insomnia

Resource Roundup:

• The TypeScript Handbook (Official) — A must-read for mastering TypeScript.
• Scala Exercises by 47 Degrees — Interactive lessons for Scala beginners and pros
• Swift Playgrounds on iPad (Apple Developer) — Learn Swift the fun and visual way.

Interview Question of the Day

Daily Interview Questions

Frontend :
1. What is reconciliation in React?
2. How does Vue’s reactivity system work under the hood?
3. Explain JSX and how it gets compiled.
4. text
5. What’s the purpose of useEffect hook in React?

Backend :
1. What is pattern matching in Scala?
2. How do you handle asynchronous code in Swift?
3. Explain memory management in R
4. What are decorators in TypeScript?

Database :
1. Explain ACID properties in databases.
2. What is denormalization? When would you use it?
3. What is a covering index?

Others :
1. What is a container orchestration tool? Give an example.
2. What is the purpose of the /etc directory in Linux?

Daily Quiz Challenge

Frontend :

1. What does useState() return in React?
2. What's the default position of an HTML element?
3. What CSS property changes the mouse cursor?

Backend :

1. What does async do in TypeScript?
2. How do you create a tuple in Scala?
3. What's the difference between let and var in Swift?

Database :

1. What is a subquery?

Others :

1. Which command lists all running Docker containers?

Mixed :

1. What's the difference between em and rem in CSS?
2. What's a closure in JavaScript?
3. What does HAVING clause do in SQL?

Weekly Cross-Domain Activities ( April 25 to May 01, 2025 )

API of the Day:

Challenge:

Use the Bored API to create a simple app that suggests fun activities when you're bored.

Linux/DevOps Tip:

Useful Commands for File & Directory Management and Troubleshooting

Here are 10 powerful and often underused commands for managing files and debugging issues in Linux systems:

1. stat filename – View detailed metadata about a file (last access, inode, etc.)
2. ls -lhS – List files by size in human-readable format
3. tree -L 2 – Display a directory structure up to 2 levels deep
4. find /path -type f -size +100M – Find files larger than 100MB
5. ncdu – A disk usage analyzer with a simple interactive UI (install required)
6. lsof +D /path/to/dir – List open files in a directory
7. inotifywait -m /some/dir – Watch for real-time file changes in a directory (from inotify-tools)
8. file filename – Determine file type and encoding
9. tail -F /var/log/syslog – Live-follow system logs with file rotation support
10. watch -n 1 'df -h / && free -h' – Watch disk and memory stats refresh every second

Real-World Project of the Week ( April 25 to May 01, 2025 )

Project of the Week:

Build a Personal Expense Tracker App

• Tech Stack Options:
• TypeScript + Express + PostgreSQL + React

Collaborative Project:

• Contribute to EddieHub Open Source Projects
• Join issues tagged good first issue on GitHub!

Case Study:

How is Notion Built?

• Uses React + TypeScript frontend
• Backend with C++/Rust hybrid for performance
• Offline-first architecture

Challenge: Try replicating a basic note-taking component!