Daily Coding Challenges & Projects

Frontend Mini Project Challenge

Theme : Mini Frontend Projects

Challenge :

Build a Dark Mode Toggle

• Use plain JavaScript or React/Vue.
• Store user preference in localStorage so the mode persists after refresh.
• Bonus : Add smooth CSS transitions between modes.

Alternative :

Build a Responsive Navbar with Hamburger Menu.

• Should collapse on small screens.
• Add animation when opening/closing.

Playground :CodeSandbox / CodePen

Backend Challenge

Category : Scala, R, Swift, TypeScript

Scala Challenge :

• Implement a REST API in Scala (Play Framework) that returns a list of books in JSON.

R Challenge :

• Write an R script to connect to a database, run a query, and export results to CSV.

Swift Server-Side Challenge :

• Create a simple API using Vapor (Swift) that returns "Hello, Backend!"

TypeScript (Node.js + Express) :

• Build a /users endpoint with CRUD operations (Create, Read, Update, Delete).

Database Query Challenge

Problems on SQL - HR Database :

1. Write a SQL query to list employees who work in more than one department.
2. Write a SQL query to find the 3 highest-paid employees in each department.

Data Structures & Algorithms Challenge

• Easy:
• Problem :Find the first non-repeating character in a string.
• Hint :Use a hash map (dictionary) to count frequencies.
• Medium:
• Problem : Implement LRU Cache using Doubly Linked List + Hash Map.
• Hint :Use OrderedDict in Python or LinkedHashMap in Java.
• Hard:
• Problem :Given a weighted graph, implement Dijkstra’s Algorithm to find the shortest path.
• Hint :Use priority queue (min-heap).

Bug of the Day

Language : Scala, R, Swift, TypeScript

Buggy Code ( TypeScript ):

function addNumbers(a: number, b: number): number {
    return a + b;
}
console.log(addNumbers("2", "3")); 

Find & Fix : What’s wrong?

📋 Daily Micro-Project

Type : Backend

Task :

Create a file upload API in Node.js + Express.

• Accept only images (jpg, png).
• Store them in a uploads/ directory.

Bonus : Add validation (file size limit 5MB).

Trivia: 5 Fun Facts

1. The first computer mouse was made of wood (1964).
2. The first computer bug was an actual moth stuck in a Harvard Mark II relay (1947).
3. JavaScript was created in just 10 days by Brendan Eich.
4. The name Python comes from “Monty Python,” not the snake.
5. The first website ever (1991) is still online: info.cern.ch.

Tool & Resource of the Day

Tool : Postman

Link : Postman

• Super useful for testing APIs.
• Supports collections, automated tests, and environment variables.

Resource Roundup :

• Free eBook: REST API Design Rulebook
• Cheat Sheet: REST API Best Practices

Interview Question of the Day

Daily Interview Questions

Frontend :
1. What’s the difference between controlled and uncontrolled components in React?
2. Explain React’s Context API and use cases.
3. What is the difference between v-if and v-show in Vue.js?
4. Explain the concept of React reconciliation.

Backend :
1. How does Node.js handle concurrency with a single thread?
2. Explain goroutines in Go.
3. What is garbage collection in Java, and how does it work?
4. Difference between Monolith and Microservices architecture.

Database :
1. What are transactions in SQL?
2. Difference between clustered and non-clustered indexes.
3. What is ACID in databases?

Others :
1. What is CI/CD? Why is it important in DevOps?
2. Explain container orchestration with Kubernetes

Daily Quiz Challenge

Frontend :

1. What hook replaces componentDidMount in React?
• useReducer
• useState
• useEffect
• useMemo
2. Which CSS property makes text bold?
• font-size
• font-weight
• text-decoration
• text-style
3. In Vue.js, which directive is used for looping?
• v-for
• v-if
• v-show
• v-bind

Backend :

1. Which language introduced goroutines?
2. What is the default port of HTTP?
3. In Python, what does __init__ do?

Mixed :

1. Database : Which SQL keyword is used to remove duplicates?
2. Other : Who created Linux?

Weekly Cross-Domain Activities ( August 22 to August 28, 2025 )

API of the Day:

Build a Weather App using OpenWeatherMap API.

Linux Tip :Use htop to monitor CPU, memory, and processes in real-time.

Real-World Project of the Week ( August 22 to August 28, 2025 )

Project of the Week:

Build a Personal Portfolio Website with HTML, CSS, and JavaScript.

Collaborative Project :

Create an Open Source Expense Tracker in React + Node.js.

Case Study :

Analyze Twitter’s infinite scrolling → implement it using React + Intersection Observer API.