About
A comprehensive collection of coding challenges from CodingChallenges.fyi and additional experimental challenges. Each challenge involves building practical programming tools, applications, and systems from scratch.
Topics covered include: system programming, CLI tools, network protocols, servers, data structures, algorithms, web applications, games, and DevOps tools.
Created by Ankur Mursalin
Filter Challenges
System Tools & CLI Utilities (1-15)
wc Tool
Word, line, character, and byte counter
JSON Parser
Parse and validate JSON
Compression Tool
File compression utility
cut Tool
Cut out selected portions of lines
Load Balancer
Distribute traffic across servers
Sort Tool
Sort lines of text files
Calculator
Command-line calculator
Redis Server
In-memory data structure store
grep
Pattern matching tool
uniq Tool
Filter duplicate lines
Web Server
HTTP server implementation
URL Shortener
Shorten and redirect URLs
diff Tool
Compare files line by line
Shell
Command-line shell
cat Tool
Concatenate and display files
Network & Communication (16-25)
IRC Client
Internet Relay Chat client
Memcached Server
Distributed memory caching
Spotify Client
Music streaming client
Discord Bot
Automated Discord bot
LinkedIn Carousel Generator
Generate carousel posts
Sed
Stream editor
DNS Resolver
Domain name resolution
Traceroute
Network path tracer
Realtime Chat
Chat client and server
NATS Message Broker
Messaging system
Development Tools (26-50)
Git
Version control system
Rate Limiter
API rate limiting
NTP Client
Network time synchronization
Scheduling Automation
Task scheduler
Lisp Interpreter
Lisp language interpreter
QR Code Generator
Generate QR codes
Crontab Tool
Schedule recurring tasks
head
Output first part of files
jq
JSON processor
Google Keep
Note-taking app
Pong
Classic arcade game
Redis CLI
Redis command-line interface
Network Modelling Tool
Network simulation
Social Media Tool
Social networking features
curl
URL data transfer tool
HTTPS Load Tester
Load testing utility
tr Tool
Translate or delete characters
Tetris
Block-stacking game
DNS Forwarder
DNS query forwarding
Port Scanner
Network port scanner
yq
YAML processor
Chrome Extension
Browser extension
Data Privacy Vault
Secure data storage
Password Cracker
Password security testing
Xargs
Build and execute commands
Advanced Systems (51-75)
HTTP Forward Proxy
HTTP proxy server
Docker
Container runtime
Spell Checker (Bloom Filter)
Spell checking using bloom filters
Tar
Archive utility
Xxd
Hexdump utility
Chess Game
Chess implementation
Snake Game
Classic snake game
Password Manager
Secure password storage
Netcat
Network utility tool
Pastebin
Code sharing service
Dropbox
File synchronization
Git Contributions Visualization
Visualize git activity
Space Invaders
Arcade shooter game
Spotify Playlist Backup
Backup playlists
Minesweeper
Classic puzzle game
Zip File Cracker
Password recovery tool
YAML Parser
Parse and validate YAML
Blogging Software
Blog platform
Notion
Note-taking workspace
Memcached CLI
Memcached command-line tool
Wheel of Names
Random name picker
Sudoku
Number puzzle game
Text Editor
Terminal text editor
Asteroids
Space shooter game
Duplicate File Finder
Find duplicate files
Applications & Advanced Tools (76-94)
Video Chat App
Real-time video communication
Static Site Generator
Generate static websites
Uptime Monitoring
Service monitoring
Socat
Socket utility
Optical Character Recognition
Text extraction from images
Brainfuck Interpreter
Esoteric language interpreter
Markdown to PDF
Convert markdown to PDF
Markdown Presentation Tool
Presentation from markdown
Mandelbrot Set Explorer
Fractal visualization
Time Zone Converter
Convert between time zones
Strace
System call tracer
Code Comment Remover
Strip code comments
Top
Process monitoring tool
ELIZA
Natural language chatbot
SMTP Server
Email server
Monkeytype
Minimalistic and customisable typing test
LOC Counter
Own version of the tools cloc, sloc and scc
Rate Limiter
API rate limiting with multiple algorithms
Forth Interpreter
Stack-based language interpreter
Div Copy Extension
Browser extension for copying div content
WordPress Form Autosave
Auto-save functionality for WordPress forms
Google Drive Downloader
Download files from a google drive folder link
Mobile IDE App
IDE for mobile use
Browser IDE v1
VS Code-like IDE that runs entirely in browser with AI assistant
Browser IDE v2
Advanced browser IDE (moved to standalone repo)
Photo Watermark Remover
Browser-based PWA for removing watermarks using OpenCV.js
Extra Challenges
Experimental and additional challenges beyond CodingChallenges.fyi
Div Copy Extension
Browser extension for copying div content
Tech: JavaScript/HTML/CSS
WordPress Form Autosave
Auto-save functionality for WordPress forms
Tech: JavaScript/PHP
Google Drive Downloader
Download files from a google drive folder link
Tech: Python
Mobile IDE App
IDE for mobile use
Tech: TypeScript/React/Capacitor
Browser IDE v1
VS Code-like IDE that runs entirely in browser with AI assistant
Tech: TypeScript/React/Monaco
Browser IDE v2
Advanced browser IDE (moved to standalone repo)
Tech: TypeScript/React
Photo Watermark Remover
Browser-based PWA for removing watermarks using OpenCV.js
Tech: TypeScript/React/OpenCV