Daily Coding Challenges & Projects

Frontend Mini Project Challenge

Theme : CSS Animation Effects

Small Challenge : Vue.js Components

Create a Vue.js component <UserBadge> that accepts three props:

• name (string)
• role (string)
• active (boolean)

Display them as a badge. If active is false, the badge should appear faded (reduced opacity).

Bonus :Emit a custom event selected when the badge is clicked.

Backend Challenge

Focus : Python, PHP

Python Challenge :

Problem : Write a Python script to stream-read a 5GB log file line-by-line, and count the number of lines that contain the word "ERROR" without loading the file into memory.

PHP Challenge :

Problem : Create a PHP function that validates a nested JSON payload and checks:

• All required keys exist
• No key has a null value
• Data types match expected types

Return a list of validation errors.

Database Query Challenge

Problems on SQL - HR Database :

1. Write a query to list employees who have not received any salary increase in the last 3 years.
2. Write a query to find departments where more than 5 employees joined within the last 6 months.

Data Structures & Algorithms Challenge

• Easy :
• Problem : Given an array of integers, return true if the array contains two adjacent numbers that sum to 10.
• Hint : Use a simple linear scan; check pair (i, i+1).
• Medium :
• Problem : Return the length of the longest increasing subsequence in an array.
• Hint : DP or binary search (O(n log n)).
• Hard :
• Problem : You are given a matrix of 0s and 1s. Find the number of distinct islands.
• Hint : Normalize coordinates of each island; compare shapes.

Bug of the Day

Focus : Python, PHP

Buggy Code ( Python ) :

nums = [1, 2, 3, 4]
squares = nums.map(lambda x: x*x)
print(squares)

Challenge : Find & fix the bug.

Buggy Code ( PHP ) :

$data = ["a" => 1, "b" => 2, "c" => 3];
foreach ($data as $key, $value) {
   echo "$key => $data[$key]\n";
}

Challenge : Find & fix the error.

📋 Daily Micro-Project

Focus : Database

Task :

Optimize a slow query on the employees table that filters by:

• department
• salary range
• hire date

Goal :Create the best possible composite index and justify why.

Trivia: 5 Fun Facts

1. The first computer bug was an actual moth stuck in the Harvard Mark II in 1947.
2. Python was named after Monty Python, not the snake.
3. Vue.js was created by Evan You, after working at Google on Angular.
4. The first 1GB disk (1980) cost $40,000.
5. PHP originally stood for Personal Home Page.

Tool & Resource of the Day

Tool : Postman

A powerful tool for testing and automating APIs.

Resource Roundup ( Vue.js ) :

• Vue.js official docs
• Vue Mastery free beginner videos
• Awesome Vue (GitHub curated list)

Interview Question of the Day

Daily Interview Questions

Frontend ( Vue.js Focus ) :
1. What are Vue.js computed properties and how do they differ from methods?
2. Explain how Vue’s reactivity system works under the hood.
3. What is the purpose of v-model in Vue.js?
4. What is the difference between props and state in Vue?

Backend ( Python & PHP ) :
1. How does memory management work in Python?
2. What is the difference between synchronous and asynchronous execution in Python?
3. How does PHP handle sessions internally?
4. Explain how Python’s GIL affects performance.

Database ( SQL ) :
1. What is the difference between INNER JOIN and LEFT JOIN?
2. What is a clustered index?
3. How does normalization improve database design?

Others ( OS + DevOps ) :
1. What is a system call? Provide an example.
2. What is the difference between virtualization and containerization?

Daily Quiz Challenge

Frontend :

1. What does v-bind do in Vue.js?
2. What is the Vue.js lifecycle hook used for AJAX requests?
3. What will be the output of:
4. console.log(typeof null);

Backend :

1. What is the output of len("hello\n") in Python?
2. In PHP, what does === check for?
3. Which Python module is used for async programming?

Database :

1. Which clause is used to filter grouped rows?

Other :

1. What does CI/CD stand for?

Weekly Cross-Domain Activities ( November 28 to December 04, 2025 )

API of the Day:

Use the Currency Exchange API to convert an amount between currencies.

Linux / DevOps Tip :

Run server health check :

top  
htop  
df -h  
du -sh *  
free -m  
uptime  
journalctl -xe  
systemctl status <service>

Real-World Project of the Week ( November 28 to December 04, 2025 )

Project of the Week:

Build a URL shortener app ( frontend + backend + database ).

Collaborative Project :

Join an open-source project:

“Awesome-DSA-Practice”

(Create algorithms + solutions in multiple languages.)

Case Study :

Analyze how Spotify recommendation engine works.

Users replicate the feature using:

• Cosine similarity
• TF-IDF
• Collaborative filtering