Daily Coding Challenges & Projects

Frontend Mini Project Challenge

Theme : Mini Frontend Projects

Challenge :

Create a Dark Mode Toggle

• Use HTML, CSS, and JavaScript (or React/Vue if you want)
• Store the user’s preference in localStorage so it persists after reload.

Bonus : Add a smooth transition effect between light and dark modes.

Hint : You can toggle a dark class on the body and define different color variables in CSS.

Backend Challenge

Category : Scala, R, Swift, TypeScript

Challenge :

Create a REST API in TypeScript ( Node.js + Express ) that:

• GET /random-quote returns a random motivational quote from an array.
• POST /add-quote adds a new quote to the array.
• Data should be stored in memory (no DB required for now).

Bonus : Add request validation using a TypeScript interface and respond with errors if invalid.

Database Query Challenge

Problems on SQL - HR Database :

1. Find the top 5 highest-paid employees
2. Find employees who joined in the last 6 months

Data Structures & Algorithms Challenge

• Easy:
• Problem :Check if a string is a palindrome (ignore spaces & case).
• Hint :Use replace(/\s/g, '') to remove spaces before checking.
• Medium:
• Problem : Implement a stack that supports getMin() in O(1) time.
• Hint :Use an auxiliary stack to store minimum values.
• Hard:
• Problem :Given an array, find the maximum sum of a subarray (Kadane’s Algorithm).
• Hint :Keep track of max_ending_here and max_so_far.

Bug of the Day

Language : TypeScript

Buggy Code:

function greetUser(name: string) {
  return "Hello, " + name.toUppercase();
}
console.log(greetUser("Alex"));

Challenge : Find and fix the issue.

📋 Daily Micro-Project

Type : Backend

Task :

Build a small API in Swift (Vapor) that:

• Returns current server time on /time endpoint.

Bonus : Format time in ISO 8601 format.

Trivia: 5 Fun Facts

1. TypeScript was created by Microsoft in 2012.
2. Scala combines object-oriented and functional programming.
3. R is one of the most popular languages for data science.
4. Swift was announced by Apple in 2014 at WWDC.
5. JavaScript was originally called Mocha.

Tool & Resource of the Day

Tool : Insomnia

Use : A modern REST API client.

• Great for testing REST and GraphQL APIs.
• Has environment variable support and automated testing.

Interview Question of the Day

Daily Interview Questions

Frontend :
1. How do CSS variables work, and why use them over SASS variables?
2. Explain event bubbling in JavaScript.
3. What are controlled vs uncontrolled components in React?
4. How does Vue.js handle reactivity?

Backend :
1. What are TypeScript interfaces and how do they differ from types?
2. Explain how Scala handles immutability.
3. How does R handle data frames internally?
4. What are Swift optionals and why are they useful?

Database :
1. What is a clustered index?
2. Explain the difference between UNION and UNION ALL.
3. How can you prevent SQL injection?

Others :
1. What is a CDN and how does it improve performance?
2. Explain the CAP theorem in distributed systems.

Daily Quiz Challenge

Frontend ) :

1. What is the output?

console.log(typeof null);

2. Which CSS property is used to make text bold?
3. In Vue.js, what does the v-if directive do?

Backend :

1. Which TypeScript keyword is used to define a constant?
2. What is the primary purpose of the case class in Scala?
3. Which function in R is used to get the first few rows of a dataset?

Mixed :

1. Database : Which SQL clause is used to group rows that have the same values?
2. Other : Who maintains the Swift programming language?

Weekly Cross-Domain Activities ( August 15 to August 21, 2025 )

API of the Day:

Build a currency converter using the ExchangeRate API

Real-World Project of the Week ( August 15 to August 21, 2025 )

Project of the Week:

Idea : Build a personal expense tracker

• Frontend : React + Tailwind CSS
• Backend : Node.js + Express + MongoDB
• Features : Add, edit, delete expenses; filter by date and category; show monthly summaries.