LeetLab

LeetLab is a full-stack coding practice platform with problem solving, real-time code execution, submissions, playlists, and a monthly leaderboard.

Features

• Email/password auth with OTP email verification and JWT cookie sessions
• Problem browsing with search, difficulty/status filters, and solved tracking
• Problem detail workspace with Monaco editor, run/submit, per-testcase feedback, and custom test cases
• Local code persistence per problem/language
• User profile analytics (submissions, solved count, language usage, streak calendar)
• Playlist management (create, update, delete, add/remove problems, progress tracking)
• Monthly leaderboard with weighted scoring (Easy=1, Medium=3, Hard=5)
• Admin-only problem creation/update/delete flow with multi-step form wizard
• Command palette (Ctrl/Cmd + K) and keyboard shortcuts in coding workspace
• Health endpoints with DB and RapidAPI checks

Tech Stack

• Frontend: React 19, TypeScript, Vite, Tailwind CSS v4, DaisyUI, React Query, Zustand, Monaco Editor
• Backend: Node.js, Express 5, Prisma ORM
• Database: PostgreSQL
• Code execution: Judge0 CE via RapidAPI
• Email: Resend

Repository Structure

LeetLab/
├── backend/   # Express + Prisma API
└── frontend/  # React + Vite client

Quick Start

Prerequisites

• Node.js 18+
• npm
• PostgreSQL
• RapidAPI key for Judge0 CE
• Resend API key (for OTP emails)

1) Clone

git clone https://github.com/Blazeiscoding/LeetLab.git
cd LeetLab

2) Backend setup

cd backend
npm install

Create backend/.env:

DATABASE_URL=postgresql://USER:PASSWORD@HOST:5432/DB_NAME
DIRECT_DATABASE_URL=postgresql://USER:PASSWORD@HOST:5432/DB_NAME
JWT_SECRET=replace_with_a_long_random_secret
RAPIDAPI_KEY=your_rapidapi_key
RAPIDAPI_BASE_URL=https://judge0-ce.p.rapidapi.com
RAPIDAPI_HOST=judge0-ce.p.rapidapi.com
RESEND_API_KEY=your_resend_api_key
RESEND_FROM_EMAIL=noreply@example.com
PORT=8080
NODE_ENV=development

Run migrations and start backend:

npm run migrate
npm run dev

3) Frontend setup

cd ../frontend
npm install

Create frontend/.env:

VITE_BACKEND_URL=http://localhost:8080/api/v1

Start frontend:

npm run dev

Open http://localhost:5173.

Environment Variables

Backend (backend/.env):

• DATABASE_URL (required): Prisma PostgreSQL connection string
• DIRECT_DATABASE_URL (required for migrations): direct PostgreSQL URL
• JWT_SECRET (required): JWT signing secret
• RAPIDAPI_KEY (required): Judge0 RapidAPI key
• RAPIDAPI_BASE_URL (optional): defaults to https://judge0-ce.p.rapidapi.com
• RAPIDAPI_HOST (optional): defaults to judge0-ce.p.rapidapi.com
• RESEND_API_KEY (required): Resend API key for OTP emails
• RESEND_FROM_EMAIL (optional): sender email
• ALLOWED_ORIGINS (optional): comma-separated extra CORS origins
• COOKIE_DOMAIN (optional): production cookie domain
• PORT (optional): API port (default 5000)
• RENDER_EXTERNAL_URL (optional): used by production keep-alive cron
• NODE_ENV (optional): development or production

Frontend (frontend/.env):

• VITE_BACKEND_URL (recommended): API base URL, e.g. http://localhost:8080/api/v1

Scripts

Backend (backend/package.json):

• npm run dev - run API with nodemon
• npm run start - run API with node
• npm run migrate - apply Prisma migrations (prisma migrate deploy)
• npm run build - install deps + Prisma generate + migrate deploy (deployment-oriented)

Frontend (frontend/package.json):

• npm run dev - start Vite dev server
• npm run build - production build
• npm run preview - preview production build
• npm run lint - run ESLint

API Overview

Base URL: /api/v1

• Auth: /auth/register, /auth/login, /auth/send-otp, /auth/verify-otp, /auth/logout, /auth/me
• Problems: /problems/get-all-problems, /problems/get-problem/:id, /problems/get-solved-problems
• Admin problems: /problems/create-problem, /problems/update-problem/:id, /problems/delete-problem/:id
• Execution: /execute-code/run, /execute-code/submit
• Submissions: /submission/get-all-submission, /submission/get-submission/:problemid, /submission/get-submissions-count/:problemid
• Playlists: /playlist, /playlist/:playlistId, /playlist/create-playlist, /playlist/:playlistId/add-problem, /playlist/:playlistId/remove-problem
• Leaderboard: /leaderboard/monthly, /leaderboard/user-stats
• Health: /health, /ping

Database and Seed Data

Prisma models include:

• User, OTP
• Problem, Submission, TestCaseResult, ProblemSolved
• Playlist, ProblemInPlaylist

Optional seed script:

cd backend
node seed.js

Note: seed.js expects at least one existing admin user.

Postman

Postman collection is available at:

• backend/postman/LeetLab-Api.postman_collection.json

Acknowledgments

• Judge0 CE
• Prisma
• React
• PostgreSQL