🧑‍⚖️ DevJudge — Online Code Practice & Evaluation Platform

DevJudge is a full-stack online code practice and evaluation platform inspired by tools like HackerRank and LeetCode. It allows users to write, run, and evaluate Java code in real time through a clean web interface backed by a secure, scalable backend.

This project was built end-to-end during a hackathon, following industry-grade workflows, AI-assisted code reviews, and cloud deployments.

🌐 Live Demo

Frontend (Vercel) 👉 https://devjudge-frontend.vercel.app/

Backend (Render) 👉 https://devjudge-backend.onrender.com

🎯 Problem Statement

Learning to code requires instant feedback, safe execution, and clear results. DevJudge solves this by providing:

A browser-based code editor

Secure backend code execution

Real-time output & error reporting

A foundation for future contests, leaderboards, and problem management

🚀 Key Features (Current & Planned)

🔜 Planned / Extensible Features

Coding problem CRUD (Trainer)

Problem listing & filtering (Student)

Test / Contest creation

Code submissions & verdicts

Leaderboards & analytics

Multi-language support

🛠 Tech Stack

Backend

Java 17

Spring Boot

Spring Security

JWT Authentication

Maven

REST APIs

Docker

Render (Deployment)

Frontend

React (Vite)

JavaScript

Fetch API

Vercel (Deployment)

Dev & Tooling

IntelliJ IDEA

Git & GitHub

Postman

AI-assisted PR reviews

🧠 Code Execution Flow (Judge Engine)

User writes Java code in browser

Frontend sends code → /api/judge/run

Backend:

Writes code to temp file

Compiles using javac

Executes safely

Captures output / errors

Result is returned to frontend

User sees output instantly

🔐 Authentication Flow

User registers with role

Password is hashed using BCrypt

Login returns JWT token

Token can be used for secured APIs (future expansion)

🤖 Code Quality & AI-Assisted Reviews (CodeRabbit)

This repository uses CodeRabbit AI to maintain high code quality and follow open-source best practices.

How CodeRabbit is used:

Automated Pull Request reviews

Suggestions on:

REST API design

Response handling (ResponseEntity)

Code structure & readability

Iterative improvements by applying AI feedback

All major changes are made via feature branches → pull requests, reviewed by CodeRabbit before merging into main.

This ensures:

Clean commit history

Maintainable architecture

Professional development workflow

📂 Project Structure (Backend)

🔐 Authentication Flow

Users register with role (TRAINER / STUDENT)

Passwords are securely hashed using BCrypt

Login returns a JWT token

JWT is used to protect secured APIs

🧪 API Testing

APIs are tested using Postman.

Example endpoints:

POST /api/auth/register

POST /api/auth/login

POST /api/judge/run

🌍 Deployment (Planned)

Backend: Render

Frontend (future): Vercel

🏁 Hackathon Notes

All development was done during the hackathon

PR-based workflow followed throughout

AI-assisted reviews (CodeRabbit) used transparently

Project is open-source and extensible

👤 Author

Aditya Patil

Backend & Full-Stack Developer

Java • Spring Boot • React • Cloud Deployment