LeetStart is a full-stack coding platform built to understand how LeetCode works behind the scenes — from frontend UI to code execution and authentication flow.
Developed entirely from scratch using React, Express, Judge0, and TailwindCSS.
| Layer | Technology |
|---|---|
| Frontend | React, Vite, Zustand, TailwindCSS |
| Backend | Node.js, Express.js, Swagger |
| Code Execution | Judge0 REST API |
| Authentication | JWT, bcrypt, OAuth (Google/GitHub in progress) |
| Database | PostgreSQL |
| Deployment | Vercel (Frontend), Render / AWS EC2 (Backend) |
- 💻 Real-time Code Execution — powered by Judge0 REST API
- 🔐 User Authentication — JWT-based; Google/GitHub OAuth coming soon
- 📚 Problem Management System — create, fetch, and solve coding problems
- ⚙️ Microservice-Ready Architecture — separate Auth and Platform services
- 🥩 Frontend–Backend Decoupling — independent deployment pipelines
- 📈 Developer-Friendly API Docs — auto-generated via Swagger
leetstart/ ├── frontend/ # React + TailwindCSS client └── backend/ # Express + Judge0 + PostgreSQL server
git clone https://github.com/aloksingh1st/leetstart.git
cd leetstart
cd backend
npm install
cp .env.example .env
npm run dev
⚠️ Make sure your .env is configured with PostgreSQL URI, JWT secret, and Judge0 API credentials.
cd ../frontend
npm install
npm run dev
🧩 Environment Variables (Backend)
Variable Description
DATABASE_URL PostgreSQL connection string
JWT_SECRET Secret key for JWT authentication
JUDGE0_URL Base URL for Judge0 API
PORT Backend server port
🥪 Development Philosophy
LeetStart isn’t just another LeetCode clone — it’s a technical exploration into:
how online judges safely manage remote code execution
how frontend–backend communication happens asynchronously
how microservices can stay modular yet connected
This project evolves as I deepen my understanding of system design, authentication flows, and developer tooling.
🧰 Future Plans
✅ Complete Google & GitHub OAuth integration
✅ Add discussion threads for each problem
🚧 Implement submission history & test case analytics
🚧 Introduce problem difficulty tagging and leaderboard
🚀 Build SDK for client-side code execution integration
👨💻 Author
Alok Singh
Full-Stack Developer | Building Entrix
& LeetStart
🔗 LinkedIn
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📜 License
MIT License © 2025 Alok Singh