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📘 Anti Plagiarism Interface

A scalable and secure microservices-based code assessment platform designed to:

• Detect plagiarism
• Execute untrusted code safely
• Evaluate coding submissions in real-time
• Support large-scale usage for colleges, coding contests, and hiring platforms

The platform is engineered for high performance, security, and maintainability using modern distributed backend architecture.

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🚀 Features

✅ Microservices Architecture

Each component is independently deployable, scalable, and communicates over gRPC for extremely low-latency performance.

✅ Secure Code Execution (Judge0 + Docker)

• Executes untrusted code inside isolated Docker sandboxes
• Protects against infinite loops, memory exploits, fork bombs, etc.
• Supports multiple programming languages

✅ Real-Time Results

Users receive immediate execution output and detailed submission history.

✅ Plagiarism Detection

Supports multiple similarity-checking techniques:

• Token-based similarity
• AST structural comparison
• Custom rule-based heuristics

✅ User Roles

• Student — submit solutions, view results, track history
• Instructor / Admin — manage questions & test cases, monitor analytics

✅ Highly Scalable

• Handles 1000+ concurrent users
• Achieves <300ms average API response time using gRPC + caching

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🧱 Tech Stack

Layer	Technologies
Frontend	React.js, Axios, Bootstrap
Backend	Java, Spring Boot, Spring Security, gRPC, JPA
Service Discovery	Eureka Server
API Gateway	Spring Cloud Gateway
Config Server	Spring Cloud Config
Database	MySQL
Cache	Redis
Code Execution	Judge0, Docker Sandbox
Build Tools	Maven
Others	Lombok, ModelMapper

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📂 Microservices Overview

Backend/
│── ApiGateway/
│── AuthService/
│── ConfigServer/
│── EurekaServer/
│── JudgeGrpcWrapper/
│── QuestionManagement/
│── SubmissionService/
│── TestCaseService/
│── UserHistoryManagement/
│── judge0-v1.13.1/   (Optional local Judge0 instance)

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🏗 System Architecture

(Add your Architecture.png below this section)

+------------------------------+
|         React Frontend       |
+-------------+----------------+
              |
              v
+------------------------------+
|        API Gateway           |
+-------------+----------------+
              |
   +----------+-------------+
   |                        |
   v                        v
+--------+          +---------------+
| Auth   | <------> |  User History |
|Service |          | Management    |
+--------+          +---------------+

+-----------------+   +-------------------+
| Question Mgmt   |   | Submission Service |
+-----------------+   +-------------------+

+-------------------------------------+
|        Test Case Service            |
+-------------------------------------+

+-------------------------------------+
|  Judge0 gRPC Wrapper (Docker)       |
+-------------------------------------+

+-------------------------------------+
| Eureka Server + Config Server       |
+-------------------------------------+

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🔑 Service Breakdown

1️⃣ AuthService

Handles:

• User registration & login
• JWT authentication
• Role-based access control

2️⃣ QuestionManagementService

Manages:

• Adding, updating & deleting questions
• Difficulty tagging
• Question metadata

3️⃣ TestCaseService

Stores:

• Public test cases
• Hidden (private) evaluation test cases

4️⃣ SubmissionService

Responsible for:

• Sending code to JudgeGrpcWrapper
• Matching output with test cases
• Returning results to users

5️⃣ JudgeGrpcWrapper

A gRPC wrapper around Judge0 that:

• Executes code in Docker
• Applies CPU/memory/time limits
• Prevents malicious behavior

6️⃣ UserHistoryManagementService

Stores:

• Submission history
• Execution status
• Time analysis
• Verdict reports (AC, WA, TLE, MLE, RE, CE)

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⚙️ How to Run the Project

1️⃣ Start the Config Server

cd Backend/ConfigServer
mvn spring-boot:run

2️⃣ Start Eureka Server

cd Backend/EurekaServer
mvn spring-boot:run

3️⃣ Start All Microservices

Repeat:

cd Backend/<ServiceName>
mvn spring-boot:run

4️⃣ Run Judge0 Docker Container

docker pull judge0/judge0
docker run -d -p 2358:2358 judge0/judge0

(Or use your custom JudgeGrpcWrapper)

5️⃣ Run the Frontend

cd Frontend
npm install
npm start

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📊 API Flow Example

1. Student submits code
2. SubmissionService receives request
3. Sends to JudgeGrpcWrapper
4. Wrapper sends to Judge0 sandbox
5. Execution result returned
6. Stored in UserHistory
7. Sent back to frontend

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📈 Performance Benchmarks

• Handles 1000+ concurrent users
• Achieves <300ms avg response time
• Horizontally scalable microservice design

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🛡 Security Features

• JWT authentication
• Role-based authorization
• Docker-based sandbox execution
• Input validation
• Optional throttling / rate limiting

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📝 Future Enhancements

• AI-driven plagiarism detection (ML-based similarity scoring)
• Leaderboards & competitive programming mode
• WebSocket real-time updates
• Admin analytics dashboard (graphs, insights)

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🤝 Contributions

Contributions are welcome! Feel free to open issues or submit pull requests.

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🧑‍💻 Author

Shrihari Kulkarni Backend Developer | Microservices | Cloud | ML 🔗 GitHub: https://github.com/shrihari7396
🔗 LinkedIn: https://www.linkedin.com/in/shrihari-kulkarni-467767299/

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